Distribution of SSR Tracts Among Coding and Noncoding Regions forEscherichia coli
| Genome-wide | Coding | Noncoding | |||
| no. | no. | % | no. | % | |
| Mononucleotides[i] (bp) | |||||
| 3 | 163,345 | 127,407 | 78.0 | 35,938 | 22.0 |
| 4 | 42,901 | 31,777 | 74.1 | 11,124 | 25.9 |
| 5 | 13,837 | 9,830 | 71.0 | 4,007 | 29.0 |
| 6 | 4,123 | 2,696 | 65.4 | 1,427 | 34.6 |
| 7 | 1,000 | 544 | 54.4 | 456 | 45.6 |
| 8 | 217 | 92 | 42.4 | 125 | 57.6 |
| 9 | 22 | 12 | 54.5 | 10 | 45.5 |
| 10 | 1 | 0 | 0.0 | 1 | 100.0 |
| Dinucleotides >6 | 7,575 | 5,779 | 76.3 | 1,796 | 23.7 |
| Trinucleotides >9 | 2,419 | 1,989 | 82.2 | 430 | 17.8 |
| Tetranucleotides | 52 | 41 | 78.9 | 11 | 21.1 |
| Genome partition | — | — | 79.5 | 20.5 | |
[i] The regression of proportion of mononucleotides SSR tracts in noncoding region on tract length is y = 6.8 x − 1.77, where y is the predicted proportion in noncoding and x is tract length. The correlation coefficient was ρ = 0.96, with a = 6.8, which is significant with p < 0.005.