Overlapped genes in E.coli. Overlapped yaaW [UniProtKB:P75617] and htgA [UniProtKB:P28697] genes in E. coli. Numbers indicate nucleotide residue for yaaW gene. The initiation codon of hgtA has been predicted to be in nucleotide 632 , and more recently in 527 . A gray box indicates the region where we have detected a lowering in the rate of evolution of yaaW sequences with an htgA overlapped gene.