期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：1993
卷号：90
期号：2
页码：577-581
DOI：10.1073/pnas.90.2.577
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：During anaerobic growth of Escherichia coli an oxygen-sensitive ribonucleoside-triphosphate reductase, different from the aerobic ribonucleoside diphosphate-reductase (EC 1.17.4.1 ), produces the deoxyribonucleoside triphosphates required for DNA replication. The gene for the anaerobic enzyme has now been cloned and was found to contain a 2136-nucleotide coding region, corresponding to 712 amino acid residues, and an Fnr binding site 228 base pairs upstream of the initiator ATG. The deduced amino acid sequence shows 72% identity to a gene of coliphage T4, sunY, hitherto of unknown function, suggesting that the virus codes for its own anaerobic reductase. The location of an organic free radical formed during activation of the bacterial anaerobic reductase is proposed to be on Gly-681, since the pentapeptide RVCGY at positions 678-682 shows a striking similarity to the C-terminal sequence. RVSGY, of pyruvate formate-lyase. During activation of the anaerobically induced pyruvate formate-lyase, the glycine residue of the pentapeptide becomes an organic radical [Wagner, A. F. V., Frey, M., Neugebauer, F. A., Schafer, W. & Knappe, J. (1992) Proc. Natl. Acad. Sci. USA 89, 996-1000]. The gene for the anaerobic reductase is located at a position around 96 min on the E. coli genomic map.
