Chemical structure of the cell wall of Mycobacterium smegmatis. I — Isolation and partial characterization of the peptidoglycan

Petit, Jean‐François; Adam, Arlette; Wietzerbin-Falszpan, J.; Lederer, E.; Ghuysen, Jean‐Marie

doi:10.1016/0006-291x(69)90371-4

Cited by 81 publications

(36 citation statements)

References 13 publications

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“…Previous studies used the drug D-cycloserine, which inhibits D-Ala-D-Ala ligase, to block incorporation of PG precursors into the PG in order to generate sufficient precursor material for analysis. They found that all muramic acids were N glycolylated (11,233,315,399). Recently, using a technique that does not require blocking PG synthesis, researchers found that mycobacterial PG contains both N-glycolyl and N-acetyl modifications (254).…”

Section: Cell Wall Components What Is the Structure Of The Mycobactermentioning

confidence: 99%

Bacterial Growth and Cell Division: a Mycobacterial Perspective

Hett

Rubín

2008

Microbiol Mol Biol Rev

342

293

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SUMMARY The genus Mycobacterium is best known for its two major pathogenic species, M. tuberculosis and M. leprae, the causative agents of two of the world's oldest diseases, tuberculosis and leprosy, respectively. M. tuberculosis kills approximately two million people each year and is thought to latently infect one-third of the world's population. One of the most remarkable features of the nonsporulating M. tuberculosis is its ability to remain dormant within an individual for decades before reactivating into active tuberculosis. Thus, control of cell division is a critical part of the disease. The mycobacterial cell wall has unique characteristics and is impermeable to a number of compounds, a feature in part responsible for inherent resistance to numerous drugs. The complexity of the cell wall represents a challenge to the organism, requiring specialized mechanisms to allow cell division to occur. Besides these mycobacterial specializations, all bacteria face some common challenges when they divide. First, they must maintain their normal architecture during and after cell division. In the case of mycobacteria, that means synthesizing the many layers of complex cell wall and maintaining their rod shape. Second, they need to coordinate synthesis and breakdown of cell wall components to maintain integrity throughout division. Finally, they need to regulate cell division in response to environmental stimuli. Here we discuss these challenges and the mechanisms that mycobacteria employ to meet them. Because these organisms are difficult to study, in many cases we extrapolate from information known for gram-negative bacteria or more closely related GC-rich gram-positive organisms.

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Section: Cell Wall Components What Is the Structure Of The Mycobactermentioning

confidence: 99%

Bacterial Growth and Cell Division: a Mycobacterial Perspective

Hett

Rubín

2008

Microbiol Mol Biol Rev

342

293

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“…Although the basic structure of peptidoglycan remains the same among eubacterial species, there are significant variations (16, 29). The structure of the mycobacterial peptidoglycan is an example of such divergence (16,27,40). The glycan chains of mycobacterial peptidoglycan are composed of alternating units of ␤134-linked GlcNAc and N-glycolylmuramic acid (MurNGlyc) in which the N-acetyl function has been oxidized to an N-glycolyl function.…”

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Mycobacterial Lipid II Is Composed of a Complex Mixture of Modified Muramyl and Peptide Moieties Linked to Decaprenyl Phosphate

et al. 2005

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Structural analysis of compounds identified as lipid I and II fromMycobacterium smegmatis demonstrated that the lipid moiety is decaprenyl phosphate; thus, M. smegmatis is the first bacterium reported to utilize a prenyl phosphate other than undecaprenyl phosphate as the lipid carrier involved in peptidoglycan synthesis. In addition, mass spectrometry showed that the muropeptides from lipid I are predominantly N-acetylmuramyl-L-alanine-D-glutamate-meso-diaminopimelic acid-D-alanyl-D-alanine, whereas those isolated from lipid II form an unexpectedly complex mixture in which the muramyl residue and the pentapeptide are modified singly and in combination. The muramyl residue is present as N-acetylmuramic acid, N-glycolylmuramic acid, and muramic acid. The carboxylic functions of the peptide side-chains of lipid II showed three types of modification, with the dominant one being amidation. The preferred site for amidation is the free carboxyl group of the meso-diaminopimelic acid residue. Diamidated species were also observed. The carboxylic function of the terminal D-alanine of some molecules is methylated, as are all three carboxylic acid functions of other molecules. This study represents the first structural analysis of mycobacterial lipid I and II and the first report of extensive modifications of these molecules. The observation that lipid I was unmodified strongly suggests that the lipid II intermediates of M. smegmatis are substrates for a variety of enzymes that introduce modifications to the sugar and amino acid residues prior to the synthesis of peptidoglycan.Peptidoglycans are essential components of bacterial cell walls, providing both mechanical strength and shape. The basic structure of peptidoglycan is common among most of the eubacteria, consisting of glycan chains composed of alternating units of ␤134-linked N-acetylglucosamine (GlcNAc) and N-acetylmuramic acid (MurNAc). The lactyl group of the MurNAc residue usually carries a short peptide (L-Ala-DGlu-meso-diaminopimelic acid [DAP]-D-Ala-D-Ala) that forms bonds with the peptide side chains of neighboring glycan strands, thus providing mechanical strength (35). Although the basic structure of peptidoglycan remains the same among eubacterial species, there are significant variations (16, 29). The structure of the mycobacterial peptidoglycan is an example of such divergence (16,27,40). The glycan chains of mycobacterial peptidoglycan are composed of alternating units of ␤134-linked GlcNAc and N-glycolylmuramic acid (MurNGlyc) in which the N-acetyl function has been oxidized to an N-glycolyl function. The carbon-6 position of some of the muramic acid residues forms a phosphodiester bond with the ␣-L-rhamnopyranose-(133)-␣-D-GlcNAc(1-P) linker region of the galactan chain of the arabinogalactan (24), and about a third of the peptide cross bridges occur between the carboxyl group of the L-center of one DAP residue and the amino group of the D-center of another DAP residue, forming a L,D-cross-link (40); the rest of the cross-links are between the carbo...

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“…23 Bacillus cereus AHU 1356 and T strains (4)(5)(6), and N-glycolylation on the muramyl residue in some strains of mycobacteria and nocardiae. PETIT, ADAM, and others (7,8) reported that Mycobacterium smegmatis had an atypical glycan strand in its cell wall which was identified to be a repeated unit of disaccharide, N-acetylglucosaminyl-~3-1,4-N-glycolylmuramic acid, which was soon demonstrated by AzUMA et al (9) to be also present in three other mycobacteria but not in Corynebacterium fermentans or Streptomyces albus. The same glycan structure was also found in three strains of Nocardia (10,11).…”

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confidence: 99%

“…However, the method for determination of glycan structure so far reported is considerably time-consuming and laborious. The procedure involves preparation of a purified cell wall, enzymic fragmentation, gel filtration, and chromatographic or mass spectrometric identification (7)(8)(9)(10)(11).…”

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confidence: 99%