Kalman M, Murphy H, Cashel M
Laboratory of Molecular Genetics, National Institute of Child Health and Human Development, Bethesda, MD 20892.
Gene. 1992 Jan 2;110(1):95-9. doi: 10.1016/0378-1119(92)90449-y.
A gene is identified in the Escherichia coli K-12 spo operon as recG. Previously identified genes in the spo operon were spoS, alias rpoZ, encoding the omega (omega) subunit of RNA polymerase, as well as the spoT gene encoding the major cellular source of guanosine 3',5'-bispyrophosphate hydrolase activity. The gene order within the spo operon is: spoS (rpoZ), spoT, spoU, recG. A convergent gltS gene is present beyond the spo operon. Mutants bearing recG deletion-insertion alleles display mild sensitivities to both ultraviolet irradiation and to mitomycin C, which is expected to be due to a known recG insertion allele. Deletion-insertion mutations in upstream operon genes (spoT and spoU) show polar effects on these assays of recG function. The deduced 693-amino acid (aa) RecG sequence shows a weak, but significant, relatedness to aa sequence motifs previously reported for putative helicases involved in replication, recombination, and DNA repair.
在大肠杆菌K-12 spo操纵子中鉴定出一个基因，即recG。spo操纵子中先前鉴定出的基因有spoS（别名rpoZ），它编码RNA聚合酶的ω（欧米伽）亚基，还有spoT基因，它编码鸟苷3',5'-双焦磷酸水解酶活性的主要细胞来源。spo操纵子内的基因顺序为：spoS（rpoZ）、spoT、spoU、recG。在spo操纵子之外存在一个与之反向的gltS基因。携带recG缺失插入等位基因的突变体对紫外线照射和丝裂霉素C均表现出轻度敏感性，这预计是由一个已知的recG插入等位基因所致。上游操纵子基因（spoT和spoU）中的缺失插入突变对这些recG功能检测显示出极性效应。推导的693个氨基酸（aa）的RecG序列与先前报道的参与复制、重组和DNA修复的假定解旋酶的氨基酸序列基序显示出微弱但显著的相关性。
