Structural analyses of the deduced amino acid sequences of a novel type heme-copper terminal oxidase, cytochrome aco3, from alkalophilic Bacillus YN-2000.
Cytochrome aco3 from a facultatively alkalophilic bacterium, Bacillus YN-2000, was found to be alkaline- and heat-tolerant. To better understand the structural features of Bacillus YN-2000 cytochrome aco3, the gene encoding this enzyme was cloned and sequenced. Nucleotide sequence analyses of the region neighboring the acoI (subunit I) gene revealed that the acoII (subunit II) and acoIII (subunit III) genes were concomitantly clustered upstream and downstream of the acoI gene, respectively, forming an operon with transcriptional polarity. The deduced amino acid sequence of subunit I was highly similar to that of cytochrome caa3 from thermophilic bacterium Bacillus PS3 in which the heme a3 could be replaced with heme o. Furthermore, a marked paucity of basic amino acid residues was found in the cytochrome c-binding subunit II, which might be a result of the adaptation to a highly alkaline external milieu.
Denda
K
K
Department of Biological Sciences, Graduate School of Bioscience and Biotechnology, Tokyo Institute of Technology, Yokohama, Japan.
Oshima
A
A
Fukumori
Y
Y
D000595:Amino Acid Sequence; D001407:Bacillus / Q000737:chemistry*; D001426:Bacterial Proteins; D003001:Cloning, Molecular; D017936:Cytochrome a Group; D003580:Cytochromes / Q000737:chemistry* / Q000235:genetics; D006358:Hot Temperature; D006863:Hydrogen-Ion Concentration; D008969:Molecular Sequence Data; D017385:Sequence Homology
D001426:Bacterial Proteins; D017936:Cytochrome a Group; D003580:Cytochromes; C070113:cytochrome aco, Bacillus