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The cytotoxic early protein 77 of mycobacteriophage L5 interacts with MSMEG_3532, an L‐serine dehydratase of Mycobacterium smegmatis
Author(s) -
Rybniker Jan,
Krumbach Karin,
van Gumpel Edeltraud,
Plum Georg,
Eggeling Lothar,
Hartmann Pia
Publication year - 2011
Publication title -
journal of basic microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.58
H-Index - 54
eISSN - 1521-4028
pISSN - 0233-111X
DOI - 10.1002/jobm.201000446
Subject(s) - mycobacterium smegmatis , biochemistry , dehydratase , biology , serine , lytic cycle , amino acid , sulfurtransferase , mycobacterium , microbiology and biotechnology , mycobacterium tuberculosis , enzyme , cysteine , bacteria , virology , medicine , tuberculosis , virus , genetics , pathology
Mycobacteriophage L5 is a temperate phage infecting a broad range of mycobacterial species. Upon induction of lytic growth, L5 rapidly switches off host protein synthesis. We have recently identified the mycobacteriophage L5 early protein gp77 as a host shut‐off protein that acts growth inhibitory in the mycobacterial host when expressed through the corresponding phage promoter. Here we present data showing that this purified phage protein of unknown function specifically binds to protein MSMEG_3532 when incubated with cell lysates of Mycobacterium smegmatis . This interaction was confirmed by pull‐down assays using purified MSMEG_3532 as bait which co‐purified with gp77. The amino acid sequence of MSMEG_3532 is nearly identical to that of threonine dehydratases, serine dehydratases and an L‐threo‐3‐hydroxyaspartate dehydratase. An enzymatic assay identified this host protein as a pyridoxal‐5′‐phosphate‐dependent L‐serine dehydratase (SdhA) which converts L‐serine to pyruvate. This is the first biochemical characterization of a SdhA derived from mycobacteria. Though the addition of purified gp77 to the established in vitro assay had no influence on SdhA activity at a saturating L‐serine concentration, the specific interaction of phage protein and dehydratase in vivo may well have a role in altering the amino acid pool or the products of amino acid metabolism in favour of phage maturation. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)