title: whmD is an essential mycobacterial gene required for proper septation and cell division.
abstract: A study of potential mycobacterial regulatory genes led to the isolation of the Mycobacterium smegmatis whmD gene, which encodes a homologue of WhiB, a Streptomyces coelicolor protein required for sporulation. Unlike its Streptomyces homologue, WhmD is essential in M. smegmatis. The whmD gene could be disrupted only in the presence of a plasmid supplying whmD in trans. A plasmid that allowed chemically regulated expression of the WhmD protein was used to generate a conditional whmD mutant. On withdrawal of the inducer, the conditional whmD mutant exhibited irreversible, filamentous, branched growth with diminished septum formation and aberrant septal placement, whereas WhmD overexpression resulted in growth retardation and hyperseptation. Nucleic acid synthesis and levels of the essential cell division protein FtsZ were unaltered by WhmD deficiency. Together, these phenotypes indicate a role for WhmD in mycobacterial septum formation and cell division.
authors.affiliation: Departments of Molecular Microbiology and Immunology, International Health, and Medicine, Center for Tuberculosis Research, The Johns Hopkins University, Baltimore, MD 21205, USA.
authors.forename: J E
authors.initials: JE
authors.lastname: Gomez
authors.forename: W R
authors.initials: WR
authors.lastname: Bishai
mesh_terms: D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D001483:Base Sequence; D002455:Cell Division; D003598:Cytoskeletal Proteins; D004269:DNA, Bacterial; D005798:Genes, Bacterial; D005816:Genetic Complementation Test; D008969:Molecular Sequence Data; D020102:Mycobacterium smegmatis / Q000166:cytology / Q000235:genetics / Q000254:growth & development* / Q000648:ultrastructure
chemical_list: D001426:Bacterial Proteins; D003598:Cytoskeletal Proteins; D004269:DNA, Bacterial; C071525:FtsZ protein, Bacteria; C412372:WhmD protein, Mycobacterium smegmatis