Displaying publications 41 - 60 of 4087 in total

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  1. A new cold-adapted, organic solvent stable lipase from mesophilic Staphylococcus epidermidis AT2
    Kamarudin NH, Rahman RN, Ali MS, Leow TC, Basri M, Salleh AB
    Protein J, 2014 Jun;33(3):296-307.
    PMID: 24777627 DOI: 10.1007/s10930-014-9560-3
    The gene encoding a cold-adapted, organic solvent stable lipase from a local soil-isolate, mesophilic Staphylococcus epidermidis AT2 was expressed in a prokaryotic system. A two-step purification of AT2 lipase was achieved using butyl sepharose and DEAE sepharose column chromatography. The final recovery and purification fold were 47.09 % and 3.45, respectively. The molecular mass of the purified lipase was estimated to be 43 kDa. AT2 lipase was found to be optimally active at pH 8 and stable at pH 6-9. Interestingly, this enzyme demonstrated remarkable stability at cold temperature (<30 °C) and exhibited optimal activity at a temperature of 25 °C. A significant enhancement of the lipolytic activity was observed in the presence of Ca(2+), Tween 60 and Tween 80. Phenylmethylsulfonylfluoride, a well known serine inhibitor did not cause complete inhibition of the enzymatic activity. AT2 lipase exhibited excellent preferences towards long chain triglycerides and natural oils. The lipolytic activity was stimulated by dimethylsulfoxide and diethyl ether, while more than 50 % of its activity was retained in methanol, ethanol, acetone, toluene, and n-hexane. Taken together, AT2 lipase revealed highly attractive biochemical properties especially because of its stability at low temperature and in organic solvents.
    Matched MeSH terms: Bacterial Proteins/genetics; Bacterial Proteins/isolation & purification; Bacterial Proteins/metabolism; Bacterial Proteins/chemistry*; Recombinant Proteins/genetics; Recombinant Proteins/isolation & purification; Recombinant Proteins/metabolism; Recombinant Proteins/chemistry*
  2. Fulltext Survivin expression correlates with unfavourable prognoses in invasive ductal carcinoma of the breast
    Al-Joudi FS, Iskandar ZA, Imran AK
    Med J Malaysia, 2007 Mar;62(1):6-8.
    PMID: 17682561 MyJurnal
    Survivin is a 16.5-kDa intracellular protein also known as AP14 or BIRC5. It inhibits apoptosis and regulates cell division and belongs to the inhibitors of apoptosis (IAP) gene family. In the majority of neoplasms investigated for survivin expression, high levels of the IAP proteins were predictive of tumour progression, either in terms of disease-free survival or overall survival, thus providing significant prognostic information. Hence, the prognostic value of survivin expression in tumour masses of invasive ductal carcinoma has been investigated. It was found that negative and low expression of survivin correlated significantly with favourable outcomes. Conversely, high expression correlated with unfavourable outcomes. The five-year survival rate was higher among the cases with low and negative survivin expression, compared to those with higher survivin expression. However, this correlation was found to be insignificant statistically. Furthermore, a statistical model has been devised to explain the combined effects of survivin expression and its sub-cellular localisation, p-53 expression and lymph nodal involvement, on the outcomes of these patients.
    Matched MeSH terms: Microtubule-Associated Proteins/analysis*; Microtubule-Associated Proteins/antagonists & inhibitors; Neoplasm Proteins/analysis*; Neoplasm Proteins/antagonists & inhibitors; Inhibitor of Apoptosis Proteins
  3. Evaluation of different promoters driving the GFP reporter gene and selected target tissues for particle bombardment of Dendrobium Sonia 17
    Tee CS, Marziah M, Tan CS, Abdullah MP
    Plant Cell Rep, 2003 Jan;21(5):452-8.
    PMID: 12789448
    Three different morphological callus types, identified as type A, B and C, and tips of in vitro inflorescences were used as target tissues for genetic transformation. Five different DNA plasmids carrying a synthetic green fluorescent protein (gfp) gene driven by different promoters, CaMV 35S, HBT, and Ubi1 were tested for the genetic transformation of Dendrobium Sonia 17. 35S-sgfp-TYG-nos (p35S) with the CaMV 35S promoter showed the highest GFP transient expression rate, while the HBT and Ubi1 promoters showed a relatively lower expression rate in all of the target tissues tested. The highest number of GFP-expressing cells was observed on day 2 post-bombardment, and the number declined gradually over the course of the next 2 weeks. Type A and B callus were found to be the best potential target tissues for genetic transformation.
    Matched MeSH terms: Luminescent Proteins/genetics; Luminescent Proteins/metabolism; Recombinant Fusion Proteins/genetics; Recombinant Fusion Proteins/metabolism; Green Fluorescent Proteins
  4. Fulltext The Sequence-specific Peptide-binding Activity of the Protein Sulfide Isomerase AGR2 Directs Its Stable Binding to the Oncogenic Receptor EpCAM
    Mohtar MA, Hernychova L, O'Neill JR, Lawrence ML, Murray E, Vojtesek B, et al.
    Mol Cell Proteomics, 2018 04;17(4):737-763.
    PMID: 29339412 DOI: 10.1074/mcp.RA118.000573
    AGR2 is an oncogenic endoplasmic reticulum (ER)-resident protein disulfide isomerase. AGR2 protein has a relatively unique property for a chaperone in that it can bind sequence-specifically to a specific peptide motif (TTIYY). A synthetic TTIYY-containing peptide column was used to affinity-purify AGR2 from crude lysates highlighting peptide selectivity in complex mixtures. Hydrogen-deuterium exchange mass spectrometry localized the dominant region in AGR2 that interacts with the TTIYY peptide to within a structural loop from amino acids 131-135 (VDPSL). A peptide binding site consensus of Tx[IL][YF][YF] was developed for AGR2 by measuring its activity against a mutant peptide library. Screening the human proteome for proteins harboring this motif revealed an enrichment in transmembrane proteins and we focused on validating EpCAM as a potential AGR2-interacting protein. AGR2 and EpCAM proteins formed a dose-dependent protein-protein interaction in vitro Proximity ligation assays demonstrated that endogenous AGR2 and EpCAM protein associate in cells. Introducing a single alanine mutation in EpCAM at Tyr251 attenuated its binding to AGR2 in vitro and in cells. Hydrogen-deuterium exchange mass spectrometry was used to identify a stable binding site for AGR2 on EpCAM, adjacent to the TLIYY motif and surrounding EpCAM's detergent binding site. These data define a dominant site on AGR2 that mediates its specific peptide-binding function. EpCAM forms a model client protein for AGR2 to study how an ER-resident chaperone can dock specifically to a peptide motif and regulate the trafficking a protein destined for the secretory pathway.
    Matched MeSH terms: Proteins/genetics; Proteins/metabolism*; Recombinant Proteins/metabolism; Proto-Oncogene Proteins c-mdm2/metabolism
  5. Nodamura virus B2 amino terminal domain sensitivity to small interfering RNA
    Ali PS, John J, Selvaraj M, Kek TL, Salleh MZ
    Microbiol. Immunol., 2015 May;59(5):299-304.
    PMID: 25753649 DOI: 10.1111/1348-0421.12253
    Nodamura virus (NoV) B2, a suppressor of RNA interference, binds double stranded RNAs (dsRNAs) and small interfering RNAs (siRNAs) corresponding to Dicer substrates and products. Here, we report that the amino terminal domain of NoV B2 (NoV B2 79) specifically binds siRNAs but not dsRNAs. NoV B2 79 oligomerizes on binding to 27 nucleotide siRNA. Mutation of the residues phenylalanine49 and alanine60 to cysteine and methionine, respectively enhances the RNA binding affinity of NoV B2 79. Circular dichroism spectra demonstrated that the wild type and mutant NoV B2 79 have similar secondary structure conformations.
    Matched MeSH terms: Viral Proteins/genetics; Viral Proteins/metabolism*; RNA-Binding Proteins/genetics; RNA-Binding Proteins/metabolism*; Mutant Proteins/genetics; Mutant Proteins/metabolism
  6. Immunoproteomic analysis of antibody response to cell wall-associated proteins of Candida tropicalis
    Lee PY, Gam LH, Yong VC, Rosli R, Ng KP, Chong PP
    J Appl Microbiol, 2014 Sep;117(3):854-65.
    PMID: 24909754 DOI: 10.1111/jam.12562
    This study was conducted to identify antigenic proteins of Candida tropicalis that are targeted by the host immune system.
    Matched MeSH terms: Fungal Proteins/analysis; Fungal Proteins/genetics; Fungal Proteins/immunology*; Membrane Proteins/analysis; Membrane Proteins/immunology*; Recombinant Proteins/immunology
  7. Induction and characterization of heat shock proteins of Salmonella typhi and their reactivity with sera from patients with typhoid fever
    Tang SW, Abubakar S, Devi S, Puthucheary S, Pang T
    Infect Immun, 1997 Jul;65(7):2983-6.
    PMID: 9199477
    The heat shock protein (HSP) response of Salmonella typhi following exposure to elevated growth temperatures was studied. Three major proteins with molecular sizes of 58, 68, and 88 kDa were abundantly expressed when S. typhi cells were shifted from 37 to 45 degrees C and to 55 degrees C. These proteins were also constitutively expressed at 37 degrees C. Western blotting and immunoprecipitation studies with anti-HSP monoclonal antibodies revealed that the 58- and 68-kDa proteins were analogous to the GroEL and DnaK proteins, respectively, of Escherichia coli. These HSPs are also abundantly present in the outer membrane fraction of disrupted cells and, to a lesser extent, in the cytosol. Immunoblotting experiments with sera from patients with a culture-positive diagnosis of typhoid fever showed the presence of antibodies to these HSPs. Nine of twelve sera reacted with the 58-, 68-, and 88-kDa proteins, while three sera reacted only with the 68- and 88-kDa proteins. All 10 sera from healthy individuals showed no binding to these HSPs. In light of the well-documented roles of HSPs in the pathogenesis of microbial infections and as immunodominant antigens, these findings may be relevant for a better understanding of disease processes and for the future development of diagnostic and preventive strategies.
    Matched MeSH terms: Bacterial Proteins/immunology; Heat-Shock Proteins/analysis*; Heat-Shock Proteins/immunology*; HSP70 Heat-Shock Proteins/immunology; Escherichia coli Proteins*
  8. Expression and characterization of anticoagulant activity of salivary protein alALP from Asian tiger mosquito Aedes albopictus
    Li XP, Lin D, Zhang Y, Chen SQ, Bai HQ, Zhang SN, et al.
    Trop Biomed, 2020 Mar 01;37(1):116-126.
    PMID: 33612723
    Several bioactive molecules isolated from the saliva of blood-sucking arthropods, such as mosquitoes, have been shown to exhibit potential anticoagulant function. We have previously identified a 30kDa allergen named Aegyptin-like protein (alALP), which is highly homologous to Aegyptin, from the salivary glands of female Aedes albopictus (Asian tiger mosquito). In this study, we identified the conserved functional domain of alALP by using bioinformatic tools, and expressed the His-tagged alALP recombinant protein in sf9 insect cells by generation and transfection of a baculoviral expression plasmid carrying the fulllength cDNA of alALP. We purified this recombinant protein and examined its function on the inhibition of blood coagulation. The results showed that the purified His-alALP prolonged the Activated Partial Thromboplastin Time (APTT), Prothrombin Time (PT) and Thrombin Time (TT) in vitro as well as the Bleeding Time (BT) in vivo, which suggest that alALP could be a novel anticoagulant.
    Matched MeSH terms: Recombinant Proteins/genetics; Recombinant Proteins/chemistry; Salivary Proteins and Peptides/genetics; Salivary Proteins and Peptides/chemistry*; Insect Proteins/genetics; Insect Proteins/chemistry*
  9. Inclusion bodies of recombinant Epstein-Barr virus capsid antigen p18 as potential immobilized antigens in enzyme immunoassays for detection of nasopharyngeal carcinoma
    Lim CS, Goh SL, Kariapper L, Krishnan G, Lim YY, Ng CC
    Clin Chim Acta, 2015 Aug 25;448:206-10.
    PMID: 26164385 DOI: 10.1016/j.cca.2015.07.008
    Development of indirect enzyme-linked immunosorbent assays (ELISAs) often utilizes synthetic peptides or recombinant proteins from Escherichia coli as immobilized antigens. Because inclusion bodies (IBs) formed during recombinant protein expression in E. coli are commonly thought as misfolded aggregates, only refolded proteins from IBs are used to develop new or in-house diagnostic assays. However, the promising utilities of IBs as nanomaterials and immobilized enzymes as shown in recent studies have led us to explore the potential use of IBs of recombinant Epstein-Barr virus viral capsid antigen p18 (VCA p18) as immobilized antigens in ELISAs for serologic detection of nasopharyngeal carcinoma (NPC).
    Matched MeSH terms: Recombinant Proteins/immunology; Recombinant Proteins/chemistry; Capsid Proteins/immunology*; Capsid Proteins/chemistry; Immobilized Proteins/immunology*; Immobilized Proteins/chemistry
  10. Phage display antibodies for diagnostic applications
    Hairul Bahara NH, Tye GJ, Choong YS, Ong EB, Ismail A, Lim TS
    Biologicals, 2013 Jul;41(4):209-16.
    PMID: 23647952 DOI: 10.1016/j.biologicals.2013.04.001
    With major developments in molecular biology, numerous display technologies have been successfully introduced for recombinant antibody production. Even so, phage display still remains the gold standard for recombinant antibody production. Its success is mainly attributed to the robust nature of phage particles allowing for automation and adaptation to modifications. The generation of monospecific binders provides a vital tool for diagnostics at a lower cost and higher efficiency. The flexibility to modify recombinant antibodies allows great applicability to various platforms for use. This review presents phage display technology, application and modifications of recombinant antibodies for diagnostics.
    Matched MeSH terms: Recombinant Proteins/biosynthesis; Recombinant Proteins/genetics
  11. Gene expression and functional studies of small heat shock protein 37 (MrHSP37) from Macrobrachium rosenbergii challenged with infectious hypodermal and hematopoietic necrosis virus (IHHNV)
    Arockiaraj J, Vanaraja P, Easwvaran S, Singh A, Othman RY, Bhassu S
    Mol Biol Rep, 2012 Jun;39(6):6671-82.
    PMID: 22290288 DOI: 10.1007/s11033-012-1473-7
    In this study, we have reported a full length of small heat shock protein 37 (designated MrHSP37) gene, identified from the transcriptome database of freshwater prawn Macrobrachium rosenbergii. The complete gene sequence of the MrHSP37 is 2,425 base pairs in length, and encodes 338 amino acids. MrHSP37 contains a long heat shock protein family profile in the amino acid sequence between 205 and 288. The mRNA expressions of MrHSP37 in healthy and the infectious hypodermal and hematopoietic necrosis virus (IHHNV) challenged M. rosenbergii were examined using quantitative real time polymerase chain reaction (qRT-PCR). MrHSP37 is highly expressed in hepatopancreas and all the other tissues (walking leg, gills, muscle, stomach, haemocyte, intestine, pleopods, brain and eye stalk) of M. rosenbergii taken for analysis. The expression is strongly up-regulated after IHHNV challenge. To understand its biological activity, the recombinant MrHSP37 gene was constructed and expressed in Escherichia coli BL21 (DE3). The results of ATPase assay showed that the recombinant MrHSP37 protein exhibited apparent ATPase activity which increased with the concentration of the protein. And also the purified recombinant MrHSP37 protein was used for thermal aggregation assay (chaperone activity). It showed that the recombinant MrHSP37 protein is an active chaperone in this assay. Taken together, these results suggest that MrHSP37 is potentially involved in the immune responses against IHHNV challenge in M. rosenbergii.
    Matched MeSH terms: Recombinant Proteins/genetics; Recombinant Proteins/metabolism; Recombinant Proteins/chemistry; Heat-Shock Proteins, Small/genetics*; Heat-Shock Proteins, Small/metabolism; Heat-Shock Proteins, Small/chemistry; Arthropod Proteins/genetics*; Arthropod Proteins/metabolism; Arthropod Proteins/chemistry
  12. NES-REBS: A novel nuclear export signal prediction method using regular expressions and biochemical properties
    Wu T, Wang X, Zhang Z, Gong F, Song T, Chen Z, et al.
    J Bioinform Comput Biol, 2016 06;14(3):1650013.
    PMID: 27225342 DOI: 10.1142/S021972001650013X
    A nuclear export signal (NES) is a protein localization signal, which is involved in binding of cargo proteins to nuclear export receptor, thus contributes to regulate localization of cellular proteins. Consensus sequences of NES have been used to detect NES from protein sequences, but suffer from poor predictive power. Some recent peering works were proposed to use biochemical properties of experimental verified NES to refine NES candidates. Those methods can achieve high prediction rates, but their execution time will become unacceptable for large-scale NES searching if too much properties are involved. In this work, we developed a novel computational approach, named NES-REBS, to search NES from protein sequences, where biochemical properties of experimental verified NES, including secondary structure and surface accessibility, are utilized to refine NES candidates obtained by matching popular consensus sequences. We test our method by searching 262 experimental verified NES from 221 NES-containing protein sequences. It is obtained that NES-REBS runs in 2-3[Formula: see text]mins and performs well by achieving precision rate 47.2% and sensitivity 54.6%.
    Matched MeSH terms: Proteins/metabolism*; Proteins/chemistry*
  13. Fulltext Genomic characterization of bacteria from the ultra-oligotrophic Madison aquifer: insight into the archetypical LuxI/LuxR and identification of novel LuxR solos
    Wengert PC, Wong NH, Barton HA, Gan HM, Hudson AO, Savka MA
    BMC Res Notes, 2021 May 08;14(1):175.
    PMID: 33964980 DOI: 10.1186/s13104-021-05589-6
    OBJECTIVES: To characterize the bacterial community of Wind Cave's Madison aquifer through whole-genome sequencing, and to better understand the bacterial ecology by identifying genes involved in acyl-homoserine lactone (AHL) based quorum-sensing (QS) systems.

    RESULTS: Genome-based taxonomic classification revealed the microbial richness present in the pristine Madison aquifer. The strains were found to span eleven genera and fourteen species, of which eight had uncertain taxonomic classifications. The genomes of strains SD129 and SD340 were found to contain the archetypical AHL QS system composed of two genes, luxI and luxR. Surprisingly, the genomes of strains SD115, SD129, SD274 and SD316 were found to contain one to three luxR orphans (solos). Strain SD129, besides possessing an archetypical AHL QS luxI-luxR pair, also contained two luxR solos, while strain SD316 contained three LuxR solos and no luxI-luxR pairs. The ligand-binding domain of two LuxR solos, one each from strains SD129 and SD316, were found to contain novel substitutions not previously reported, thus may represent two LuxR orphans that detection and response to unknown self-produced signal(s), or to signal(s) produced by other organisms.

    Matched MeSH terms: Bacterial Proteins/genetics; Repressor Proteins
  14. Improved DNA delivery using invasive E. coli DH10B in human cells by modified bactofection method
    Sultana A, Tiash S
    J Control Release, 2021 04 10;332:233-244.
    PMID: 33561481 DOI: 10.1016/j.jconrel.2021.02.004
    E. coli mediated gene delivery faces a major drawback of low efficiency despite of being a safer alternative to viral vectors. This study showed a novel, simple and effective strategy to enhance invasive E. coli DH10B vector's efficiency in human epithelial cells. The bactofection efficiency of invasive E .coli vector was analyzed in nine cell lines. It demonstrated highest (16%) reporter gene (GFP) expression in cervical cells. Methods were employed to further enhance its efficiency by adding transfection reagents (trans-bactofection method) to promote entry into host cells, lysosomotropic reagents for escape from lysosomal degradation or antibiotics to lyse internalized bacteria. Increased bacterial entry, as elucidated from nil to 3% expression in liver cells, was obtained upon complexing bacteria with PULSin. Chloroquine mediated endosomal escape resulted in 7.2 folds increase whereas tetracycline addition to lyse internalized bacteria caused ≈90% of GFP in HeLa. Eventually, the combined effect of these three methods exhibited close to 100% GFP in cervical and remarkable increase of 138 folds in breast cells. This is the first study showing comparative study of vector's gene delivery ability in various epithelial cells of the human body with improving its delivery efficiency. These data demonstrated the potential of developed bactofection method to boost up the efficiency of other bacterial vectors also, which could further be used for effectual therapeutic gene delivery in human cells.
    Matched MeSH terms: Bacterial Outer Membrane Proteins; Escherichia coli Proteins*
  15. Fulltext Observations of travelling ionospheric disturbances during storm events over Antarctica
    Momani, M.A., Yatim, B., Ali, M.A.M., Abdullah, M.
    ASM Science Journal, 2009;3(2):121-130.
    MyJurnal
    The paper examines the propagation direction and speed of large scale travelling ionospheric disturbances (LSTIDs) obtained from GPS observations of extreme geomagnetic storms during the 23rd solar cycle; these are the October 2003 and November 2003 geomagnetic storms. In the analysis, the time delay between total electron content (TEC) structures at Scott Base station (SBA) (Lat. –77.85º, Long. 166.76º), McMurdo (McM4), (Lat. –77.84º, Long. 166.95º), Davis (DAV1), (Lat. –68.58º, Long. 77.97º) and Casey station (CAS1) (Lat. –66.28º, Long. 110.52º) GPS stations as well as the distance between these stations were employed in the analysis. The measurements during the October 2003 storm showed obvious time delay between the TEC enhancement occurrences at SBA/MCM4, DAV1 and CAS1 stations. The time delay indicated a movement of the ionospheric structures from higher to lower latitudes in a velocity ranging between 0.8 km/s – 1.2 km/s. The first sudden TEC enhancement was observed at SBA/McM4 (Lat. –75.84º) followed by CAS1 station (Lat. –66.28º) and the final TEC enhancement was seen at DAV1 station (Lat. –68.58º) with TEC magnitude decreasing while moving from higher to lower latitudes. One important observation was that although the latitude of the CAS1 station was lower than the DAV1 station, the TEC enhancement was firstly seen at the CAS1 station due to the shorter distance between SBA and CAS1 compared with the distance between SBA and CAS1 of about 500 km. The TEC measurements during the November 2003 storm showed an opposite propagation direction (i.e. poleward direction from lower to higher latitudes) which was seen with a velocity ranging between 0.3 km/s – 0.4 km/s. As similar response was observed using vertical TEC measurements obtained from individual PRN satellites but with higher velocity ranges (1.2 km/s – 2.4 km/s during October
    and 0.5 km/s – 0.7 km/s during November). The equatorward or poleward expansion of LSTIDs during the October and November 2003 storms was probably caused by the disturbances in the neutral temperature which occurred close to the dayside convection throat or due to the neutral wind oscillation induced by atmospheric gravity waves launched from the aurora region.
    Matched MeSH terms: DNA-Binding Proteins; Nuclear Proteins; Cell Cycle Proteins
  16. Structural probing of HapR to identify potent phytochemicals to control Vibrio cholera through integrated computational approaches
    Tahir Ul Qamar M, Ahmad S, Khan A, Mirza MU, Ahmad S, Abro A, et al.
    Comput Biol Med, 2021 11;138:104929.
    PMID: 34655900 DOI: 10.1016/j.compbiomed.2021.104929
    Cholera is a severe small intestine bacterial disease caused by consumption of water and food contaminated with Vibrio cholera. The disease causes watery diarrhea leading to severe dehydration and even death if left untreated. In the past few decades, V. cholerae has emerged as multidrug-resistant enteric pathogen due to its rapid ability to adapt in detrimental environmental conditions. This research study aimed to design inhibitors of a master virulence gene expression regulator, HapR. HapR is critical in regulating the expression of several set of V. cholera virulence genes, quorum-sensing circuits and biofilm formation. A blind docking strategy was employed to infer the natural binding tendency of diverse phytochemicals extracted from medicinal plants by exposing the whole HapR structure to the screening library. Scoring function criteria was applied to prioritize molecules with strong binding affinity (binding energy 
    Matched MeSH terms: Bacterial Proteins/genetics; Bacterial Proteins/metabolism
  17. VapC toxin switches M. smegmatis cells into dormancy through 23S rRNA cleavage
    Zamakhaev M, Grigorov A, Bespyatykh J, Azhikina T, Goncharenko A, Shumkov M
    Arch Microbiol, 2022 Dec 15;205(1):28.
    PMID: 36520276 DOI: 10.1007/s00203-022-03363-1
    Mycobacterium tuberculosis is an extremely successful pathogen known for its ability to cause latent infection. The latter is connected with the bacterium resting state development and is considered to be based on the activity of toxin-antitoxin (TA) systems at least in part. Here we studied the physiological and proteomic consequences of VapC toxin overexpression together with the features of the protein synthesis apparatus and compared them with the characteristics of dormant mycobacterial cells in an M. smegmatis model. The findings allow suggesting the mechanism mycobacteria enter dormancy, which is realized through VapC-caused cleavage of the 23S rRNA Sarcin-Ricin loop followed by conservation of stalled ribosomes in a membrane-associated manner. The found features of resting mycobacteria protein synthesis apparatus hypothesize the mechanisms of resuscitation from dormancy through the ribosomes de-association off the membrane accompanied by the 23S rRNA break curing, and could be of value for the development of principally new antituberculosis agents.
    Matched MeSH terms: Bacterial Proteins/genetics; Bacterial Proteins/metabolism
  18. Fulltext Genetic polymorphism of the thrombospondin-related apical merozoite protein (TRAMP) of Plasmodium knowlesi in Malaysia
    Ng YL, Lau YL, Hamid MHA, Jelip J, Ooi CH, Mudin RN, et al.
    Parasitol Res, 2023 Jan;122(1):195-200.
    PMID: 36378331 DOI: 10.1007/s00436-022-07716-z
    Plasmodium knowlesi is a simian malaria parasite that causes significant zoonotic infections in Southeast Asia, particularly in Malaysia. The Plasmodium thrombospondin-related apical merozoite protein (TRAMP) plays an essential role in the invasion of the parasite into its host erythrocyte. The present study investigated the genetic polymorphism and natural selection of the full length PkTRAMP from P. knowlesi clinical isolates from Malaysia. Blood samples (n = 40) were collected from P. knowlesi malaria patients from Peninsular Malaysia and Malaysian Borneo. The PkTRAMP gene was amplified using PCR, followed by cloning into a plasmid vector and sequenced. Results showed that the nucleotide diversity of PkTRAMP was low (π: 0.009). Z-test results indicated negative (purifying) selection of PkTRAMP. The alignment of the deduced amino acid sequences of PkTRAMP of Peninsular Malaysia and Malaysian Borneo revealed 38 dimorphic sites. A total of 27 haplotypes were identified from the amino acid sequence alignment. Haplotype analysis revealed that there was no clustering of PkTRAMP from Peninsular Malaysia and Malaysian Borneo.
    Matched MeSH terms: Protozoan Proteins/genetics; Protozoan Proteins/metabolism
  19. Fulltext Biofilm Signaling, Composition and Regulation in Burkholderia pseudomallei
    Nyanasegran PK, Nathan S, Firdaus-Raih M, Muhammad NAN, Ng CL
    J Microbiol Biotechnol, 2023 Jan 28;33(1):15-27.
    PMID: 36451302 DOI: 10.4014/jmb.2207.07032
    The incidence of melioidosis cases caused by the gram-negative pathogen Burkholderia pseudomallei (BP) is seeing an increasing trend that has spread beyond its previously known endemic regions. Biofilms produced by BP have been associated with antimicrobial therapy limitation and relapse melioidosis, thus making it urgently necessary to understand the mechanisms of biofilm formation and their role in BP biology. Microbial cells aggregate and enclose within a self-produced matrix of extracellular polymeric substances (EPSs) to form biofilm. The transition mechanism of bacterial cells from planktonic state to initiate biofilm formation, which involves the formation of surface attachment microcolonies and the maturation of the biofilm matrix, is a dynamic and complex process. Despite the emerging findings on the biofilm formation process, systemic knowledge on the molecular mechanisms of biofilm formation in BP remains fractured. This review provides insights into the signaling systems, matrix composition, and the biosynthesis regulation of EPSs (exopolysaccharide, eDNA and proteins) that facilitate the formation of biofilms in order to present an overview of our current knowledge and the questions that remain regarding BP biofilms.
    Matched MeSH terms: Bacterial Proteins/genetics; Bacterial Proteins/metabolism
  20. Fulltext Type II bacterial toxin-antitoxins: hypotheses, facts, and the newfound plethora of the PezAT system
    Chan WT, Garcillán-Barcia MP, Yeo CC, Espinosa M
    FEMS Microbiol Rev, 2023 Sep 05;47(5).
    PMID: 37715317 DOI: 10.1093/femsre/fuad052
    Toxin-antitoxin (TA) systems are entities found in the prokaryotic genomes, with eight reported types. Type II, the best characterized, is comprised of two genes organized as an operon. Whereas toxins impair growth, the cognate antitoxin neutralizes its activity. TAs appeared to be involved in plasmid maintenance, persistence, virulence, and defence against bacteriophages. Most Type II toxins target the bacterial translational machinery. They seem to be antecessors of Higher Eukaryotes and Prokaryotes Nucleotide-binding (HEPN) RNases, minimal nucleotidyltransferase domains, or CRISPR-Cas systems. A total of four TAs encoded by Streptococcus pneumoniae, RelBE, YefMYoeB, Phd-Doc, and HicAB, belong to HEPN-RNases. The fifth is represented by PezAT/Epsilon-Zeta. PezT/Zeta toxins phosphorylate the peptidoglycan precursors, thereby blocking cell wall synthesis. We explore the body of knowledge (facts) and hypotheses procured for Type II TAs and analyse the data accumulated on the PezAT family. Bioinformatics analyses showed that homologues of PezT/Zeta toxin are abundantly distributed among 14 bacterial phyla mostly in Proteobacteria (48%), Firmicutes (27%), and Actinobacteria (18%), showing the widespread distribution of this TA. The pezAT locus was found to be mainly chromosomally encoded whereas its homologue, the tripartite omega-epsilon-zeta locus, was found mostly on plasmids. We found several orphan pezT/zeta toxins, unaccompanied by a cognate antitoxin.
    Matched MeSH terms: Bacterial Proteins/genetics; Bacterial Proteins/metabolism
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