Growth-rate-dependent expression and cloning of gnd alleles from natural isolates of Escherichia coli.
Growth-rate-dependent expression and cloning of gnd alleles from natural isolates of Escherichia coli.
复制标题
来自大肠杆菌天然分离株的 gnd 等位基因的生长速率依赖性表达和克隆。
DOI：
10.1128/jb.170.1.365-371.1988
复制
发表时间：
1988
影响因子：
3.2
通讯作者：
WolfJr,RE
中科院分区：
文献类型：
--
作者：
Barcak,GJ;WolfJr,RE
6-磷酸葡萄糖酸脱氢酶（6PGD）基因由gnd编码，在自然界分离的大肠杆菌中具有高度多态性。作为表征生长速率依赖性调节6PGD水平的手段，五个gnd等位基因，包括E. coli B/r等位基因，与E. coliK-12与噬菌体P1的融合。在每一个同基因株中，在葡萄糖上生长的细胞中6PGD的水平比在乙酸盐上生长的细胞高2 - 3倍。在醋酸盐生长的细胞中的酶活性水平在同基因菌株组内变化约6倍。这些酶水平的差异的生理重要性进行了讨论。从5株大肠杆菌中克隆了gnd基因。大肠杆菌菌株和鼠伤寒沙门氏菌LT-2的12种限制性内切酶图谱。gnd在染色体DNA上定位定向。在保守的限制性酶切位点处对基因的限制性酶切图谱进行比对，并从限制性酶切位点多态性估计基因的相对分歧。急诊coli gnd基因与S.鼠伤寒杆菌基因降低约11%。大多数E。大肠杆菌基因彼此之间的差异小于5%，但一个等位基因与其他等位基因的差异约为10%。只有E. coliK-12中有一个IS 5元件位于附近。
6-Phosphogluconate dehydrogenase (6PGD), encoded by gnd, is highly polymorphic among isolates of Escherichia coli form natural populations. As a means of characterizing the growth-rate-dependent regulation of the level of 6PGD, five gnd alleles, including the E. coli B/r allele, were crossed into E. coli K-12 with bacteriophage P1. In each of the isogenic strains, the level of 6PGD was two- to threefold higher in cells grown on glucose than in cells grown on acetate. The level of enzyme activity in the acetate-grown cells varied about sixfold within the set of isogenic strains. The physiological importance of these differences in enzyme level is discussed. The gnd gene was cloned from five E. coli strains and Salmonella typhimurium LT-2 and mapped with twelve restriction endonucleases. gnd was located and oriented on the chromosomal DNAs. The restriction maps of the genes were aligned at conserved restriction sites, and the relative divergence of the genes was estimated from restriction site polymorphisms. The E. coli gnd genes differed from the S. typhimurium gene by about 11%. Most of the E. coli genes differed from one another by less than 5%, but one allele differed from the others by about 10%. Only the gnd gene from E. coli K-12 had an IS5 element located nearby.