Cloning of Bacillus stearothermophilus ctaA and heme A synthesis with the CtaA protein produced in Escherichia coli.
The Bacillus stearothermophilus ctaA gene, which is required for heme A synthesis, was found upstream of the ctaBCDEF/caaEABCD gene cluster as in B. subtilis and B. firmus. The deduced protein sequence indicate that CtaA is a 35-kDa intrinsic membrane protein with seven hydrophobic segments. Alignment of CtaA sequences showed conserved residues including histidines that may be involved in heme B binding and substrate binding. Expression of ctaA in E. coli resulted in increased formation of a membrane-bound b-type cytochrome, heme A production, and severe growth inhibition. Furthermore, B. stearothermophilus CtaA produced in E. coli was found to catalyze the conversion of heme O to heme A in vitro.
Sakamoto
J
J
Department of Biochemical Engineering and Science, Kyushu Institute of Technology, Fukuoka, Japan. sakamoto@bse.kyu-tech.ac.jp
Hayakawa
A
A
Uehara
T
T
Noguchi
S
S
Sone
N
N
D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000235:genetics* / Q000378:metabolism; D001483:Base Sequence; D003001:Cloning, Molecular; D003573:Cytochrome b Group / Q000235:genetics* / Q000378:metabolism*; D017931:DNA Primers / Q000235:genetics; D004269:DNA, Bacterial / Q000235:genetics; D004926:Escherichia coli / Q000235:genetics*; D015870:Gene Expression; D005798:Genes, Bacterial; D001411:Geobacillus stearothermophilus / Q000235:genetics* / Q000378:metabolism*; D006418:Heme / Q000031:analogs & derivatives* / Q000096:biosynthesis / Q000378:metabolism; D008565:Membrane Proteins / Q000235:genetics* / Q000378:metabolism*; D008969:Molecular Sequence Data; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism; D015183:Restriction Mapping; D017386:Sequence Homology, Amino Acid; D014170:Transformation, Genetic
D001426:Bacterial Proteins; C090098:CtaA protein, bacteria; D003573:Cytochrome b Group; D017931:DNA Primers; D004269:DNA, Bacterial; D008565:Membrane Proteins; D011994:Recombinant Proteins; C069808:heme O; C027728:heme a; D006418:Heme