著者

仲宗根 薫

出版者

近畿大学

雑誌

近畿大学工学部研究報告 (ISSN:0386491X)

巻号頁・発行日

vol.39, pp.15-18, 2005-12-20

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Acetyl-CoA carboxylase is key enzyme involved in the starting for fatty acid synthesis. In this study, we have cloned and sequenced gene cluster encoding acetyl-CoA carboxylase from a deep-sea piezo-and psychrophilic bacterium, Shewanella violacea strain DSS12. Sequence and structural analyses were done to understand structural-function relationships for adapting under high pressure and low temperature conditions. The cloned fragment contained two open reading frames, designated the accB and accA genes, capable of encoding a 538-amino-acid protein of 58.1 kDa and a 573-amino-acid protein of 61.5 kDa, respectively. The protein (AccA) encoded by the accA gene was strikingly similar to biotin carboxylase subunits of acetyl-CoA and propionyl-CoA carboxylases and of pyruvate carboxylase. The putative motifs for ATP binding, CO_2 fixation, and biotin binding were found in AccA. The aceB gene was located upstream of the accA gene, and they formed a two-gene operon. The protein (AccB) encoded by the aceB gene showed high degrees of sequence similarity with carboxyltransferase subunits of acetyl-CoA and propionyl-CoA carboxylases and of methylmalonyl-CoA decarboxylase. Carboxybiotin-binding and acyl-CoA-binding domains, which are conserved in several carboxyltrausferase subunits of acyl-CoA carboxylases, were found in AccB.