title: Molecular characterisation of ABC transporter type FtsE and FtsX proteins of Mycobacterium tuberculosis.
abstract: Elicitation of drug resistance and various survival strategies inside host macrophages have been the hallmarks of Mycobacterium tuberculosis as a successful pathogen. ATP Binding Cassette (ABC) transporter type proteins are known to be involved in the efflux of drugs in bacterial and mammalian systems. FtsE, an ABC transporter type protein, in association with the integral membrane protein FtsX, is involved in the assembly of potassium ion transport proteins and probably of cell division proteins as well, both of which being relevant to tubercle bacillus. In this study, we cloned ftsE gene of M. tuberculosis, overexpressed and purified. The recombinant MtFtsE-6xHis protein and the native MtFtsE protein were found localized on the membrane of E. coli and M. tuberculosis cells, respectively. MtFtsE-6xHis protein showed ATP binding in vitro, for which the K42 residue in the Walker A motif was found essential. While MtFtsE-6xHis protein could partially complement growth defect of E. coli ftsE temperature-sensitive strain MFT1181, co-expression of MtFtsE and MtFtsX efficiently complemented the growth defect, indicating that the MtFtsE and MtFtsX proteins might be performing an associated function. MtFtsE and MtFtsX-6xHis proteins were found to exist as a complex on the membrane of E. coli cells co-expressing the two proteins.
authors.affiliation: Department of Microbiology and Cell Biology, Indian Institute of Science, 560012, Bangalore, India.
authors.forename: Mushtaq Ahmad
authors.initials: MA
authors.lastname: Mir
authors.forename: Haryadi S
authors.initials: HS
authors.lastname: Rajeswari
authors.forename: Usha
authors.initials: U
authors.lastname: Veeraraghavan
authors.forename: Parthasarathi
authors.initials: P
authors.lastname: Ajitkumar
mesh_terms: D018528:ATP-Binding Cassette Transporters / Q000235:genetics* / Q000378:metabolism; D000255:Adenosine Triphosphate / Q000378:metabolism; D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000235:genetics* / Q000378:metabolism; D015153:Blotting, Western; D002455:Cell Division / Q000235:genetics; D004926:Escherichia coli / Q000235:genetics / Q000254:growth & development; D005816:Genetic Complementation Test; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D009169:Mycobacterium tuberculosis / Q000235:genetics* / Q000378:metabolism; D016366:Open Reading Frames / Q000235:genetics; D011485:Protein Binding; D017386:Sequence Homology, Amino Acid
chemical_list: D018528:ATP-Binding Cassette Transporters; D001426:Bacterial Proteins; D000255:Adenosine Triphosphate