title: Cloning, expression, and functional characterization of the Mycobacterium tuberculosis secA gene.
abstract: To better understand the protein secretion mechanisms involved in the growth and pathogenesis of Mycobacterium tuberculosis, we examined the secA gene from M. tuberculosis (tbsecA; cosmid sequence accession No. z95121.gb_ba). We generated plasmids containing the full-length tbsecA gene or a fusion containing the 5' sequence from the M. tuberculosis secA gene and the remainder from the Escherichia coli secA gene and evaluated the ability of each construct to complement the defective SecA protein in E. coli MM52ts when grown at the non-permissive temperature. The full-length tbsecA gene was unable to compensate for the temperature-sensitive defect, whereas E. coli MM52ts that has been transformed with plasmid pMF8TB226 containing a chimeric secA gene was able to grow at 42 degrees C. This work confirms that the topography of SecA and its ATP binding sites are highly conserved, whereas its membrane insertion domains are species specific.
authors.affiliation: Tuberculosis/Mycobacteriology Branch, Centers for Disease Control and Prevention, Bldg. 17, Room 4029, Mailstop FO8, Atlanta, GA 30333, USA.
authors.forename: Marie U
authors.initials: MU
authors.lastname: Owens
authors.forename: W Edward
authors.initials: WE
authors.lastname: Swords
authors.forename: Michael G
authors.initials: MG
authors.lastname: Schmidt
authors.forename: C Harold
authors.initials: CH
authors.lastname: King
authors.forename: Frederick D
authors.initials: FD
authors.lastname: Quinn
mesh_terms: D000251:Adenosine Triphosphatases / Q000235:genetics* / Q000378:metabolism / Q000502:physiology*; D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000235:genetics* / Q000378:metabolism / Q000502:physiology*; D003001:Cloning, Molecular; D004926:Escherichia coli / Q000235:genetics; D029968:Escherichia coli Proteins / Q000235:genetics* / Q000378:metabolism / Q000502:physiology*; D026901:Membrane Transport Proteins / Q000235:genetics* / Q000378:metabolism / Q000502:physiology*; D008969:Molecular Sequence Data; D009169:Mycobacterium tuberculosis / Q000201:enzymology*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D000069816:SEC Translocation Channels; D000081416:SecA Proteins; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid; D014158:Transcription, Genetic
chemical_list: D001426:Bacterial Proteins; D029968:Escherichia coli Proteins; D026901:Membrane Transport Proteins; D000069816:SEC Translocation Channels; D000251:Adenosine Triphosphatases; C465199:SecA protein, Mycobacterium tuberculosis; D000081416:SecA Proteins