NUCLEOTIDE POLYMORPHISM AND EVOLUTION IN THE GLYCERALDEHYDE-3-PHOSPHATE DEHYDROGENASE GENE (GAPA) IN NATURAL-POPULATIONS OF SALMONELLA AND ESCHERICHIA-COLI
NUCLEOTIDE POLYMORPHISM AND EVOLUTION IN THE GLYCERALDEHYDE-3-PHOSPHATE DEHYDROGENASE GENE (GAPA) IN NATURAL-POPULATIONS OF SALMONELLA AND ESCHERICHIA-COLI
复制标题
DOI：
10.1073/pnas.88.15.6667
复制
发表时间：
1991-08-01
影响因子：
11.1
通讯作者：
SELANDER, RK
中科院分区：
文献类型：
--
作者：
NELSON, K;WHITTAM, TS;SELANDER, RK
确定了从自然群体中回收的 16 株沙门氏菌菌株和 13 株大肠杆菌菌株的gapA 基因的核苷酸序列，该基因编码糖酵解酶甘油醛-3-磷酸脱氢酶。代表沙门氏菌八个血清型组的菌株的序列对平均在 3.8% 的核苷酸位点和 1.1% 的推断氨基酸上存在差异，而大肠杆菌的可比值要小一个数量级（分别为 0.2% 和 0.1%）。指定酶催化结构域的密码子的同义位点取代率显着高于编码 NAD+ 结合结构域的密码子，但非同义取代率显示相反的关系。对于沙门氏菌，多态性位点非随机聚类的统计测试未能提供证据表明基因内重组或基因转换有助于等位基因多样性的产生。由gapA序列构建的树的拓扑结构与基于多位点酶电泳的菌株的系统发育树大体相似，但沙门氏菌V组中的gapA与其他沙门氏菌和大肠杆菌菌株的分歧水平远大于整个基因组DNA杂交所表明的水平。
Nucleotide sequences of the gapA gene, encoding the glycolytic enzyme glyceraldehyde-3-phosphate dehydrogenase, were determined for 16 strains of Salmonella and 13 strains of Escherichia coli recovered from natural populations. Pairs of sequences from strains representing the eight serovar groups of Salmonella differed, on average, at 3.8% of nucleotide sites and 1.1% of inferred amino acids, and comparable values for E. coli were an order of magnitude smaller (0.2% and 0.1%, respectively). The rate of substitution at synonymous sites was significantly higher for codons specifying the catalytic domain of the enzyme than for those encoding the NAD+-binding domain, but the nonsynonymous substitution rate showed the opposite relationship. For Salmonella, statistical tests for nonrandom clustering of polymorphic sites failed to provide evidence that intragenic recombination or gene conversion has contributed to the generation of allelic diversity. The topology of a tree constructed from the gapA sequences was generally similar to that of phylogenetic trees of the strains based on multilocus enzyme electrophoresis, but the level of divergence of gapA in Salmonella group V from other Salmonella and E. coli strains is much greater than that indicated by DNA hybridization for the genome as a whole.