Riley M, Solomon L, Zipkas D
J Mol Evol. 1978 May 12;11(1):47-56. doi: 10.1007/BF01768024.
Genes of Escherichia coli were grouped according to the "biochemical relatedness" of the enzymes they specifiy, using two schemes to determine relatedness: similarity of reaction or similarity of reactants. The tendency of biochemically related genes as so defined to lie approximately 90 degrees or 180 degrees from one another on the circular genetic map was analyzed statistically. Of the classes analyzed, only the genes for the enzymes of glucose catabolism showed a significant departure from random distribution in this respect. The glucose catabolism genes showed a pronounced tendency to lie either 90 degrees of 180 degrees from one another (P = ca. 10(-9)), and, furthermore, most of these genes were found to lie in only four gene clusters on the E. coli genome. The significance of this observation is discussed in relation to evolutionary mechanisms and to mechanisms of gene expression.
根据大肠杆菌基因所指定的酶的“生化相关性”对其进行分组，使用两种方案来确定相关性：反应相似性或反应物相似性。对如此定义的生化相关基因在环状遗传图谱上彼此相距约90度或180度的趋势进行了统计分析。在所分析的类别中，就这方面而言，只有葡萄糖分解代谢酶的基因显示出与随机分布有显著差异。葡萄糖分解代谢基因表现出明显的彼此相距90度或180度的趋势（P约为10^(-9)），此外，这些基因中的大多数被发现在大肠杆菌基因组中仅位于四个基因簇中。结合进化机制和基因表达机制对这一观察结果的意义进行了讨论。
