title: Proposal concerning mechanism of evolution of the genome of Escherichia coli.
abstract: Many pairs of genes whose gene products are functionally related lie either 90 degrees or 180 degrees apart on the circular map of the E. coli chromosome. A mechanism of evolution is proposed that involves two sequential duplications of an ancestral genome, followed by mutation and divergence of function of replicate genes.
mesh_terms: D005075:Biological Evolution; D002874:Chromosome Mapping; D002876:Chromosomes, Bacterial / Q000032:analysis / Q000378:metabolism; D004261:DNA Replication; D004269:DNA, Bacterial / Q000032:analysis; D004270:DNA, Circular / Q000032:analysis; D004926:Escherichia coli / Q000032:analysis / Q000378:metabolism*; D005787:Gene Frequency; D005796:Genes; D009876:Operon
chemical_list: D004269:DNA, Bacterial; D004270:DNA, Circular