嗜热脂肪芽孢杆菌ctaA的克隆以及利用在大肠杆菌中产生的CtaA蛋白进行血红素A合成。

Cloning of Bacillus stearothermophilus ctaA and heme A synthesis with the CtaA protein produced in Escherichia coli.

作者信息

Sakamoto J, Hayakawa A, Uehara T, Noguchi S, Sone N

机构信息

Department of Biochemical Engineering and Science, Kyushu Institute of Technology, Fukuoka, Japan.

出版信息

Biosci Biotechnol Biochem. 1999 Jan;63(1):96-103. doi: 10.1271/bbb.63.96.

DOI:10.1271/bbb.63.96

PMID:10052128

Abstract

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.

摘要

嗜热脂肪芽孢杆菌ctaA基因是血红素A合成所必需的，如同在枯草芽孢杆菌和坚强芽孢杆菌中一样，它位于ctaBCDEF/caaEABCD基因簇的上游。推导的蛋白质序列表明CtaA是一种具有七个疏水片段的35 kDa内在膜蛋白。CtaA序列比对显示存在保守残基，包括可能参与血红素B结合和底物结合的组氨酸。ctaA在大肠杆菌中的表达导致膜结合b型细胞色素形成增加、血红素A产生以及严重的生长抑制。此外，发现大肠杆菌中产生的嗜热脂肪芽孢杆菌CtaA在体外催化血红素O转化为血红素A。