期刊
JOURNAL OF MOLECULAR EVOLUTION
卷 72, 期 5-6, 页码 466-473出版社
SPRINGER
DOI: 10.1007/s00239-011-9445-4
关键词
Metabolic efficiency; CpG islands; Amino acid; Conservation; Biosynthetic cost; Substitution; Bioinformatics
Protein products of highly expressed genes tend to favor amino acids that have lower average biosynthetic costs (i.e., they exhibit metabolic efficiency). While this trend has been observed in several studies, the specific sites where cost-reducing substitutions accumulate have not been well characterized. Toward that end, weighted costs in conserved and variable positions were evaluated across a total of 9,119 homologous proteins in four mammalian orders (primate, carnivore, rodent, and artiodactyls), which together contain a total of 20,457,072 amino acids. Degree of conservation at homologous positions in these mammalian proteins and average-weighted cost across all positions within a single protein are significantly correlated. Dividing human genes into two classes (those with and those without CpG islands in their promoters) suggests that humans also preferentially utilize less costly amino acids in highly expressed genes. In contrast to the intuitive expectation that the relatively weak selective force associated with metabolic efficiency would be a selection pressure in complex multicellular organisms, the overall level of selective constraint within the variable regions of mammalian proteins allows the metabolic efficiency to derive a reduction of overall biosynthetic cost, particularly in genes with the highest levels of expression.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据