Linked Life Data

10702292

Source:http://linkedlifedata.com/resource/pubmed/id/10702292

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
10
pubmed:dateCreated
2000-4-3
pubmed:abstractText
A mutant strain of Mycobacterium smegmatis defective in the biosynthesis of mycolic acids was recently isolated (Liu, J., and Nikaido, H. (1999) Proc. Natl. Acad. Sci. U. S. A. 96, 4011-4016). This mutant failed to synthesize full-length mycolic acids and accumulated a series of long chain beta-hydroxymeromycolates. In this work, we provide a detailed characterization of the localization of meromycolates and of the cell wall structure of the mutant. Thin layer chromatography showed that the insoluble cell wall matrix remaining after extraction with chloroform/methanol and SDS still contained a large portion of the total meromycolates. Matrix-assisted laser desorption/ionization and electrospray ionization mass spectroscopy analysis of fragments arising from Smith degradation of the insoluble cell wall matrix revealed that the meromycolates were covalently attached to arabinogalactan at the 5-OH positions of the terminal arabinofuranosyl residues. The arabinogalactan appeared to be normal in the mutant strain, as analyzed by NMR. Analysis of organic phase lipids showed that the mutant cell wall contained some of the extractable lipids but lacked glycopeptidolipids and lipooligosaccharides. Differential scanning calorimetry of the mutant cell wall failed to show the large cooperative thermal transitions typical of intact mycobacterial cell walls. Transmission electron microscopy showed that the mutant cell wall had an abnormal ultrastructure (without the electron-transparent zone associated with the asymmetric mycolate lipid layer). Taken together, these results demonstrate the importance of mycolic acids for the structural and functional integrity of the mycobacterial cell wall. The lack of highly organized lipid domains in the mutant cell wall explains the drug-sensitive and temperature-sensitive phenotypes of the mutant.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Mar
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
10
pubmed:volume
275
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
7224-9
pubmed:dateRevised
2009-8-10
pubmed:meshHeading
pubmed:year
2000
pubmed:articleTitle
Cell wall structure of a mutant of Mycobacterium smegmatis defective in the biosynthesis of mycolic acids.
pubmed:affiliation
Department of Medical Genetics and Microbiology, University of Toronto, Toronto, Ontario M5S 1A8, Canada.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't