title: Characterization of CrgA, a new partner of the Mycobacterium tuberculosis peptidoglycan polymerization complexes.
abstract: The role(s) in cell division of the Mycobacterium tuberculosis Rv0011c gene product, a homolog of the Streptomyces CrgA protein that is responsible for coordinating growth and cytokinesis in sporogenic aerial hyphae, is largely unknown. We show that an enhanced cyan fluorescent protein-M. tuberculosis CrgA (ECFP-CrgA(MT)) fusion protein is localized to the cell membrane, midcell, and cell pole regions in Mycobacterium smegmatis. Furthermore, the ECFP-CrgA(MT) fusion protein colocalized with FtsZ-enhanced yellow fluorescent protein (EYFP) in M. smegmatis. Bacterial two-hybrid assays indicated strong interactions of M. tuberculosis CrgA with FtsZ, FtsQ, and the class B penicillin-binding proteins, FtsI (PBPB) and PBPA. The midcell localization of CrgA(MT) was severely compromised under conditions of FtsZ depletion, which indicated that CrgA localizes to the midcell region after assembly of the FtsZ ring. M. tuberculosis cells with reduced CrgA levels were elongated and grew more slowly than wild-type cells, which indicated defects in cell division, whereas CrgA overproduction did not show growth defects. A M. smegmatis ΔcrgA strain exhibited a bulged cell morphology, elongated cells with a chain-like phenotype, cells with polar bulbous structures, and a modest growth defect. FtsZ and FtsI levels were not affected in cells producing altered levels of CrgA. Septal and membrane localization of GFP-FtsI was enhanced by CrgA overproduction and was diminished in a ΔcrgA strain, which indicates that one role of CrgA is to promote and/or stabilize FtsI localization. Overall, these data indicate that CrgA is a novel member of the cell division complex in mycobacteria and possibly facilitates septum formation.
authors.affiliation: The University of Texas Health Science Center, Tyler, TX 75708, USA.
authors.forename: P
authors.initials: P
authors.lastname: Plocinski
authors.forename: M
authors.initials: M
authors.lastname: Ziolkiewicz
authors.forename: M
authors.initials: M
authors.lastname: Kiran
authors.forename: S I
authors.initials: SI
authors.lastname: Vadrevu
authors.forename: H B
authors.initials: HB
authors.lastname: Nguyen
authors.forename: J
authors.initials: J
authors.lastname: Hugonnet
authors.forename: C
authors.initials: C
authors.lastname: Veckerle
authors.forename: M
authors.initials: M
authors.lastname: Arthur
authors.forename: J
authors.initials: J
authors.lastname: Dziadek
authors.forename: T A
authors.initials: TA
authors.lastname: Cross
authors.forename: M
authors.initials: M
authors.lastname: Madiraju
authors.forename: M
authors.initials: M
authors.lastname: Rajagopalan
mesh_terms: D001426:Bacterial Proteins / Q000032:analysis / Q000378:metabolism*; D002462:Cell Membrane / Q000737:chemistry; D003598:Cytoskeletal Proteins / Q000032:analysis; D017930:Genes, Reporter; D049452:Green Fluorescent Proteins / Q000032:analysis / Q000235:genetics; D018613:Microscopy, Confocal; D009169:Mycobacterium tuberculosis / Q000737:chemistry / Q000166:cytology / Q000235:genetics / Q000378:metabolism*; D046915:Penicillin-Binding Proteins / Q000378:metabolism; D010457:Peptidoglycan / Q000096:biosynthesis*; D011485:Protein Binding; D025941:Protein Interaction Mapping; D011993:Recombinant Fusion Proteins / Q000032:analysis / Q000235:genetics; D014157:Transcription Factors / Q000378:metabolism*; D020798:Two-Hybrid System Techniques
chemical_list: D001426:Bacterial Proteins; C406769:CrgA protein, Neisseria meningitidis; D003598:Cytoskeletal Proteins; C071525:FtsZ protein, Bacteria; D046915:Penicillin-Binding Proteins; D010457:Peptidoglycan; D011993:Recombinant Fusion Proteins; D014157:Transcription Factors; C527701:enhanced cyan fluorescent protein; D049452:Green Fluorescent Proteins