Mycobacterium tuberculosis Rv1302 and Mycobacterium smegmatis MSMEG___4947 have WecA function and MSMEG__4947 is required for the growth of M. smegmatis

Authors

  • Yue Jin,

    1. Department of Biochemistry and Molecular Biology, Dalian Medical University, Dalian, China
    Search for more papers by this author
  • Yi Xin,

    1. Department of Biotechnology; Dalian Medical University, Dalian, China
    2. Liaoning Provincial Core Lab of Glycobiology and Glycoengineering, Dalian Medical University, Dalian, China
    Search for more papers by this author
  • Wenli Zhang,

    1. Department of Biochemistry and Molecular Biology, Dalian Medical University, Dalian, China
    Search for more papers by this author
  • Yufang Ma

    1. Department of Biochemistry and Molecular Biology, Dalian Medical University, Dalian, China
    2. Liaoning Provincial Core Lab of Glycobiology and Glycoengineering, Dalian Medical University, Dalian, China
    Search for more papers by this author

  • Editor: Roger Buxton

Correspondence: Yufang Ma, Department of Biochemistry and Molecular Biology, Dalian Medical University, 9 W. Lushun South Road, Dalian 116044, China. Tel.: +86 411 8611 0338; fax: +86 411 8611 0378; e-mail: yufang_ma@hotmail.com

Abstract

The disaccharide d-N-acetylglucosamine-l-rhamnose plays an important role in the mycobacterial cell wall as a linker connecting arabinogalactan and peptidoglycan via a phosphodiester linkage. The first step of the disaccharide linker is the formation of decaprenyl phosphate-GlcNAc, which is catalyzed by GlcNAc-1-phosphate transferase. In Gram-negative bacteria, the wecA gene specifies the UDP-GlcNAc: undecaprenyl phosphate GlcNAc-1-phosphate transferase (WecA), which catalyzes the first step in the biosynthesis of lipopolysaccharide O-antigen. Mycobacterium tuberculosis Rv1302 and Mycobacterium smegmatis MSMEG_4947 show homology to Escherichia coli WecA protein. We cloned Rv1302 and MSMEG_4947 and introduced plasmids pYJ-1 (carrying Rv1302) and pYJ-2 (carrying MSMEG_4947) into a wecA-defective strain of E. coli MV501, respectively. Lipopolysaccharide analysis demonstrated that lipopolysaccharide synthesis in MV501 (pYJ-1) and MV501 (pYJ-2) was restored upon complementation with Rv1302 and MSMEG_4947, respectively. This provides the first evidence that Rv1302 and MSMEG_4947 have the same function as E. coli WecA. We also generated an M. smegmatis MSMEG_4947 knockout mutant using a homologous recombination strategy. The disruption of MSMEG_4947 in the M. smegmatis genome resulted in the loss of viability at a nonpermissive temperature. Scanning electron microscopy and transmission electron microscopy results showed that the lack of the MSMEG_4947 protein causes drastic morphological changes in M. smegmatis.

Ancillary