Li C, Peck H D, LeGall J, Przybyla A E
Department of Biochemistry, School of Chemical Sciences, University of Georgia, Athens 30602.
DNA. 1987 Dec;6(6):539-51. doi: 10.1089/dna.1987.6.539.
The structural genes for the large and small subunits of Desulfovibrio gigas periplasmic [NiFe]hydrogenase were identified and isolated by immunological and oligonucleotide screening. The gene for the small subunit codes for a 266-amino-acid, 28,724-dalton polypeptide which is separated by 63 nucleotides from the large subunit gene that codes for a 560-amino-acid, 61,707-dalton polypeptide. A putative signal peptide precedes the small subunit coding region, which may direct transport of the enzyme into the periplasmic compartment. Comparison of the amino acid sequence of this enzyme with those of two other classes of hydrogenase found in Desulfovibrio revealed that the D. gigas periplasmic hydrogenase has some homologies to the periplasmic [NiFeSe]hydrogenase of D. baculatus but none to the periplasmic [Fe]hydrogenase of D. vulgaris. The genes for the large and small subunits of the D. gigas hydrogenase hybridize strongly to genomic DNAs from several species of Desulfovibrio, indicating molecular similarity of the [NiFe]hydrogenase among sulfate reducers.
通过免疫筛选和寡核苷酸筛选，鉴定并分离出了巨大脱硫弧菌周质[NiFe]氢化酶大亚基和小亚基的结构基因。小亚基基因编码一个由266个氨基酸组成、分子量为28,724道尔顿的多肽，它与编码一个由560个氨基酸组成、分子量为61,707道尔顿多肽的大亚基基因相隔63个核苷酸。在小亚基编码区之前有一个推测的信号肽，它可能指导该酶转运到周质区室。将这种酶的氨基酸序列与在脱硫弧菌中发现的其他两类氢化酶的氨基酸序列进行比较，发现巨大脱硫弧菌周质氢化酶与杆状脱硫弧菌的周质[NiFeSe]氢化酶有一些同源性，但与普通脱硫弧菌的周质[Fe]氢化酶没有同源性。巨大脱硫弧菌氢化酶大亚基和小亚基的基因与几种脱硫弧菌的基因组DNA强烈杂交，表明硫酸盐还原菌中[NiFe]氢化酶的分子相似性。
