Abstract
By comparing, among Escherichia coli and 9 bacteriophages, repressibilities of occurrences of σ78-promoter consensus-like sequences in coding regions by means of an index (Ks) derived from x2-statistic and principal components analysis (PCA), we have demonstrated that (1-1) the repressibility of the occurrences of the consensuslike sequences in the whole genome for E.coli is the highest of all the genomes, (1-2) the repressibilities for the two temperate phages (P4 and λ) are similar to that for E. coli, and (2) the occcurrences of the consensus-like sequneces for other phages (T7, M13, fd, fl, IKe, G4, and ΦX174). These results suggest that the repressibilty of the consensus-like sequences in genomic coding regions is an important factor to effectively coordinate a web of gene control circuits, and assessment of similarities of phages to E.coli by the gene frequencies based on the two parameters (Ks and x2) and PCA has made it possible to predict whether or not phage genomes can be coordinated with E. coli genome in transcription regulation.
