Simple Sequence Repeats in Escherichia coli: Abundance, Distribution, Composition, and Polymorphism

Table 2.

Distribution of SSR Tracts Among Coding and Noncoding Regions forEscherichia coli

Genome-wide Coding Noncoding
no. no. % no. %
Mononucleotides (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
  • 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.

This Article

  1. Genome Res. 10: 62-71

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