Matsukage A, Nishikawa K, Ooi T, Seto Y, Yamaguchi M
J Biol Chem. 1987 Jul 5;262(19):8960-2.
Nucleotide sequence analysis of the cDNA and the genomic clones for rat DNA polymerase beta revealed the existence of a 1,005-base pair open reading frame capable of encoding a Mr = 38,269 polypeptide of 335 amino acid residues. The region of 174 amino acid residues between the 42nd and 215th residues of the DNA polymerase beta polypeptide has extensive amino acid sequence homology with the region between the 195th and 366th residues of human terminal deoxynucleotidyltransferase. The two enzymes share extensive homology not only in primary structures but also in the computer-derived higher structures in these particular regions. The genes for DNA polymerase beta and terminal deoxynucleotidyltransferase are proposed to be derived from a common ancestral DNA polymerase gene.
对大鼠DNA聚合酶β的cDNA和基因组克隆进行的核苷酸序列分析显示，存在一个1005个碱基对的开放阅读框，能够编码一个由335个氨基酸残基组成、分子量为38269的多肽。DNA聚合酶β多肽第42位至215位残基之间的174个氨基酸残基区域，与人末端脱氧核苷酸转移酶第195位至366位残基之间的区域具有广泛的氨基酸序列同源性。这两种酶不仅在一级结构上，而且在这些特定区域的计算机推导的高级结构上都具有广泛的同源性。DNA聚合酶β和末端脱氧核苷酸转移酶的基因被认为来源于一个共同的祖先DNA聚合酶基因。
