Purification, characterization, and gene cloning of thermophilic cytochrome cd1 nitrite reductase from Hydrogenobacter thermophilus TK-6
Purification, characterization, and gene cloning of thermophilic cytochrome cd1 nitrite reductase from Hydrogenobacter thermophilus TK-6
复制标题
DOI：
10.1263/jbb.101.391
复制
发表时间：
2006-05-01
影响因子：
2.8
通讯作者：
Igarashi, Yasuo
中科院分区：
文献类型：
--
作者：
Suzuki, Miho;Hirai, Tadao;Igarashi, Yasuo
A thermophilic, chemolithoautotrophic hydrogen-oxidizing bacterium, Hydrogenobacter thermophilus TK-6 can grow autotrophically under anaerobic conditions by denitrification. One of the denitrification enzymes, cytochrome cd(1) nitrite reductase, was isolated and its gene was cloned from strain TK-6. The subunit molecular mass of the purified enzyme was 61.5 kDa and the isoelectric point was determined to be 9.3. The optimum temperature and pH for the enzymatic reaction were 70-75 degrees C and 6.5-7.0, respectively. The structural gene for the enzyme, nirS, is probably transcribed as a hexacistronic operon with the following genes encoding a putative diheme cytochrome c and the proteins required for biosynthesis of heme d(1). The NirS sequence was phylogenetically distinct from those of proteobacteria. The consensus -35 and -10 sequences were found in the putative nirS promoter region, but the consensus sequences for the DNR/NnrR-type or the NorR/FhpR-type nitric oxide sensing regulators were not found in this region.
