Goncharoff P, Nichols B P
J Bacteriol. 1984 Jul;159(1):57-62. doi: 10.1128/jb.159.1.57-62.1984.
Biochemical and immunological experiments have suggested that the Escherichia coli enzyme p-aminobenzoate synthetase and anthranilate synthetase are structurally related. Both enzymes are composed of two nonidentical subunits. Anthranilate synthetase is composed of proteins encoded by the genes trp(G)D and trpE, whereas p-aminobenzoate synthetase is composed of proteins encoded by pabA and pabB. These two enzymes catalyze similar reactions and produce similar products. The nucleotide sequences of pabA and trp(G)D have been determined and indicate a common evolutionary origin of these two genes. Here we present the nucleotide sequence of pabB and compare it with that of trpE. Similarities are 26% at the amino acid level and 40% at the nucleotide level. We propose that pabB and trpE arose from a common ancestor and hence that there is a common ancestry of genes encoding p-aminobenzoate synthetase and anthranilate synthetase.
生化和免疫学实验表明,大肠杆菌中的对氨基苯甲酸合成酶和邻氨基苯甲酸合成酶在结构上相关。这两种酶均由两个不同的亚基组成。邻氨基苯甲酸合成酶由trp(G)D和trpE基因编码的蛋白质组成,而对氨基苯甲酸合成酶由pabA和pabB基因编码的蛋白质组成。这两种酶催化相似的反应并产生相似的产物。pabA和trp(G)D的核苷酸序列已被确定,表明这两个基因有共同的进化起源。在此,我们给出pabB的核苷酸序列,并将其与trpE的核苷酸序列进行比较。氨基酸水平的相似度为26%,核苷酸水平的相似度为40%。我们提出,pabB和trpE起源于一个共同的祖先,因此,编码对氨基苯甲酸合成酶和邻氨基苯甲酸合成酶的基因有共同的祖先。