ANCIENT ORIGIN OF LACTALBUMIN FROM LYSOZYME - ANALYSIS OF DNA AND AMINO-ACID SEQUENCES
ANCIENT ORIGIN OF LACTALBUMIN FROM LYSOZYME - ANALYSIS OF DNA AND AMINO-ACID SEQUENCES
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DOI：
10.1007/bf02101195
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发表时间：
1988-01-01
影响因子：
3.9
通讯作者：
WILSON, AC
中科院分区：
文献类型：
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作者：
PRAGER, EM;WILSON, AC
与编码溶菌酶c和α-溶菌酶的DNA序列相关的简约树乳清蛋白表明，使乳清蛋白从溶菌酶进化的基因复制早于哺乳动物和鸟类的分化。其他溶菌酶和乳清蛋白的氨基酸序列的比较与这一观点一致。当考虑所有碱基位置时，导致乳清蛋白基因的复制发生在哺乳动物进化开始之后的概率估计为0.05-0.10。消除由快速进化和密码子第三位置的组成偏差产生的系统发育噪声，将该概率降低至0.002-0.03。因此，基因复制可能早于乳清蛋白功能的获得。
Parsimony trees relating DNA sequences coding for lysozymes c and .alpha.-lactalbumins suggest that the gene duplication that allowed lactalbumin to evolve from lysozyme preceded the divergence of mammals and birds. Comparisons of the amino acid sequences of additional lysozymes and lactalbumins are consistent with this view. When all base positions are considered, the probability that the duplication leading to the lactalbumin gene occurred after the start of mammalian evolution is estimated to be 0.05-0.10. Elimination of the phylogenetic noise generated by fast evolution and compositional bias at third positions of codons reduced this probability to 0.002-0.03. Thus the gene duplication may have long preceded the acquisition of lactalbumin function.