Inactivation of the mycobacterial rhamnosyltransferase, which is needed for the formation of the arabinogalactan-peptidoglycan linker, leads to irreversible loss of viability

Mills, Jonathan A. ; Motichka, Kelly ; Jucker, Markus ; Wu, Henry P. ; Uhlik, Brian C. ; Stern, Richard J. ; Scherman, Michael S. ; Vissa, Varalakshmi D. ; Pan, Fei ; Kundu, Manikuntala ; Ma, Yu Fang ; McNeil, Michael (2004) Inactivation of the mycobacterial rhamnosyltransferase, which is needed for the formation of the arabinogalactan-peptidoglycan linker, leads to irreversible loss of viability Journal of Biological Chemistry, 279 (42). pp. 43540-43546. ISSN 0021-9258

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Official URL: http://www.jbc.org/content/279/42/43540.full

Related URL: http://dx.doi.org/10.1074/jbc.M407782200

Abstract

Temperature-sensitive mutant 2-20/32 of Mycobacterium smegmatis mc2155 was isolated and genetically complemented with a Mycobacterium tuberculosis H37Rv DNA fragment that contained a single open reading frame. This open reading frame is designated Rv3265c in the M. tuberculosis H37Rv genome. Rv3265c shows homology to the Escherichia coli gene wbbL, which encodes a dTDP-Rha:α-D-GlcNAc-pyrophosphate polyprenol, α-3-L-rhamnosyltransferase. In E. coli this enzyme is involved in O-antigen synthesis, but in mycobacteria it is required for the rhamnosyl-containing linker unit responsible for the attachment of the cell wall polymer mycolyl-arabinogalactan to the peptidoglycan. The M. tuberculosis wbbL homologue, encoded by Rv3265c, was shown to be capable of restoring an E. coli K12 strain containing an insertionally inactivated wbbL to O-antigen positive. Likewise, the E. coli wbbL gene allowed 2-20/32 to grow at higher non-permissive temperatures. The rhamnosyltransferase activity of M. tuberculosis WbbL was demonstrated in 2-20/32 as was the loss of this transferase activity in 2-20/32 at elevated temperatures. The wbbL of the temperature-sensitive mutant contained a single-base change that converted what was a proline in mc2155 to a serine residue. Exposure of 2-20/32 to higher non-permissive temperatures resulted in bacteria that could not be recovered at the lower permissive temperatures.

Item Type:Article
Source:Copyright of this article belongs to American Society for Biochemistry and Molecular Biology.
ID Code:102774
Deposited On:02 Feb 2018 04:12
Last Modified:02 Feb 2018 04:12

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