Figure 1.

The positional bias of the tested sequence motifs within genes. In each genome, the genes were divided proportionally into five quintiles (with 0–20% denoting the initial one-fifth of the gene beginning at its 5' end, and 80–100% denoting the 3' segment), and the numbers of the sequence motifs were summed for each segment. The sequence motifs are depicted with different length stringencies (8 and 10 bp): the US is 5'-(A)AAGTGCGG(T)-3' (the left two lanes per genome sequence), whereas the rcUS is 5'-(A)CCGCACTT(T)-3' (the right two lanes per genome). The accession numbers of the five tested genome sequences are NC_000907, NC_008309, NC_002663, NC_006300 and NC_009655, respectively.