Phosphorylated lipids play important roles in biological systems, not only as structural moieties but also as modulators of cellular function. Phospholipids of pathogenic bacteria are known to play roles both as membrane components and as factors that modulate the infectious process. Mycobacterium tuberculosis is, however, noteworthy in that it has an extremely diverse repertoire of biologically active phosphorylated lipids that, in the absence of a specialized protein translocation system, appear to constitute the main means of communication with the host. Many of these lipids are derived from phosphatidylinositol (PI) that is differentially processed to give rise to phosphatidylinositol mannosides (PIMs) or lipoarabinomannan. In preliminary studies on the lipid processing enzymes associated with the bacterial cell wall, a kinase activity was noted that gave rise to a novel lipid species released by the bacterium. It was determined that this kinase activity was encoded by the ORF Rv2252. Rv2252 demonstrates the capacity to phosphorylate various amphipathic lipids of host and bacterial origin, in particular a M. tuberculosis derived diacylglycerol. Targeted deletion of the rv2252 gene resulted in disruption of the production of certain higher order PIM species, suggesting a role for Rv2252 in the biosynthetic pathway of PI, a PIM precursor.
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http://dx.doi.org/10.1111/j.1365-2958.2006.05174.x | DOI Listing |
Sci Rep
December 2024
Population Health and Host Pathogen Interactions Programs, Texas Biomedical Research Institute, San Antonio, TX, USA.
In recent decades, drug resistant (DR) strains of Mycobacterium tuberculosis (M.tb), the cause of tuberculosis (TB), have emerged that threaten public health. Although M.
View Article and Find Full Text PDFInt J Syst Evol Microbiol
December 2024
Department of Biochemistry and Microbiology, Faculty of Pharmaceutical Sciences, Chulalongkorn University, 254 Phayathai Road, Wangmai, Pathumwan, Bangkok 10330, Thailand.
Three strains of actinobacteria, designated as B-S-A6, B-S-A8 and B-S-A12, were isolated from soil samples collected in the Phu Pha Phet Cave located in the Satun UNESCO Global Geopark, Satun Province, Thailand. A comprehensive polyphasic approach was used to describe these strains. Strains B-S-A6, B-S-A8 and B-S-A12 were identified within the genus based on a comparative examination of 16S rRNA gene sequences.
View Article and Find Full Text PDFInt J Syst Evol Microbiol
November 2024
Department of Public Health Laboratory Sciences, School of Public Health, Heng-yang Medical School, University of South China, Hengyang, Hunan 421001, PR China.
A novel actinomycete, designated strain ZYX-F-249, was isolated from the gill of a leopard coral grouper in Yongxing Island, Hainan Province, China. Based on 16S rRNA gene sequence analysis, strain ZYX-F-249 belonged to the genus , with high similarities to ATCC 12950 (98.7 %), 211020 (98.
View Article and Find Full Text PDFJ Antibiot (Tokyo)
November 2024
Department of Biochemistry and Microbiology, Faculty of Pharmaceutical Sciences. Chulalongkorn University, Bangkok, 10330, Thailand.
A new actinomycete strain, ODS25, exhibited antimicrobial activity against Bacillus subtilis, Kocuria rhizophila, Staphylococcus aureus, Staphylococcus epidermidis, Candida albicans, Candida tropicalis, was isolated from the ants, Odontomachus simillimus, collected from National Science Museum Thailand, Pathum Thani, Thailand. A polyphasic technique was used to characterize the taxonomic position. The morphological and chemotaxonomic properties of the strain are typical of members of the genus Streptomyces.
View Article and Find Full Text PDFNat Commun
July 2024
School of Biosciences, University of Birmingham, Birmingham, UK.
Mycobacterial glycolipids are important cell envelope structures that drive host-pathogen interactions. Arguably, the most important are lipoarabinomannan (LAM) and its precursor, lipomannan (LM), which are trafficked from the bacterium to the host via unknown mechanisms. Arabinomannan is thought to be a capsular derivative of these molecules, lacking a lipid anchor.
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