Higher gene duplicabilities for metabolic proteins than for nonmetabolic proteins in yeast and E. coli.

Although the evolutionary significance of gene duplication has long been appreciated, it remains unclear what factors determine gene duplicability. In this study we investigated whether metabolism is an important determinant of gene duplicability because cellular metabolism is crucial for the survival and reproduction of an organism. Using genomic data and metabolic pathway data from the yeast (Saccharomyces cerevisiae) and Escherichia coli, we found that metabolic proteins indeed tend to have higher gene duplicability than nonmetabolic proteins. Moreover, a detailed analysis of metabolic pathways in these two organisms revealed that genes in the central metabolic pathways and the catabolic pathways have, on average, higher gene duplicability than do other genes and that most genes in anabolic pathways are single-copy genes.