Cobalamin (vitamin B12) biosynthesis:: identification and characterization of a Bacillus megaterium cobI operon
Cobalamin (vitamin B12) biosynthesis:: identification and characterization of a Bacillus megaterium cobI operon
复制标题
DOI：
10.1042/bj3350159
复制
发表时间：
1998-10-01
影响因子：
4.1
通讯作者：
Thermes, C
中科院分区：
文献类型：
--
作者：
Raux, E;Lanois, A;Thermes, C
已从巨大芽孢杆菌基因组文库中分离出一个16 kb的DNA片段，并进行了全序列测定。该片段包含15个开放阅读框，其中14个被认为构成了一个B。巨菌钴胺素生物合成（cob）操纵子。在操纵子内，II基因显示出与先前鉴定的鼠伤寒沙门氏菌钴胺素生物合成基因（cbiH（60）、-J、-C、-D、-ET、-L、-F、-G、-A、cysG（A）和btuR）的相似性，而三个不相似（cbiW、-X和-Y）。B的基因。将巨大菌coB操纵子与铜绿假单胞菌、詹氏甲烷球菌和集胞藻的钴胺素生物合成基因进行了比较。考虑到cbiD和cbiG的存在，cobF、cobG和cobN、-S和-T的缺失，得出结论：B. megaterium，M. jannaschii和集胞藻属，像S。鼠伤寒沙门氏菌通过厌氧途径合成钴胺素，其中钴在早期阶段加入并且不需要分子氧。
A 16 kb DNA fragment has been isolated from a Bacillus megaterium genomic library and fully sequenced. The fragment contains 15 open reading frames, 14 of which are thought to constitute a B. megaterium cobalamin biosynthetic (cob) operon. Within the operon, II genes display similarity to previously identified Salmonella typhimurium cobalamin biosynthetic genes (cbiH(60), -J, -C, -D, -ET, -L, -F, -G, -A, cysG(A) and btuR), whereas three do not (cbiW, -X and -Y). The genes of the B. megaterium cob operon were compared with the cobalamin biosynthetic genes of Pseudomonas denitrificans, Methanacoccus jannaschii and Synechocystis sp. Taking into account the presence of cbiD and cbiG, the absence of a cobF, cobG and cobN, -S and -T, it was concluded that B. megaterium, M. jannaschii and Synechocystis sp., like S. typhimurium, synthesize cobalamin by an anaerobic pathway, in which cobalt is added at an early stage and molecular oxygen is not required.