A circular code in the protein coding genes of mitochondria

[摘要] A new maximal circular code X-0(MIT) with two permutated maximal circular codes X-1(MIT) and X-2(MIT) is identified in the protein coding genes of mitochondria. The three subsets of 20 trinucleotides X-0(MIT)= {ACA, ACC, ATA, ATC, CTA, CTC, GAA, GAG, GAT, GCA, GCC, GCT, GGA, GGC, GGT, GTA, GTC, GTT, TTA, TTC), X-1(MIT) and X-2(MIT) are in frame 0 (reading frame), 1 and 2 respectively. X-1(MIT) and X-2(MIT) are deduced by one and two circular permutations of X-0(MIT) respectively. The code X-0(MIT) has four important properties: a length of the minimal window to automatically retrieve frame 0 which is equal to five nucleotides; an occurrence probability equal to 6.3 x 10(-5); a low frequency (12% in average) of misplaced trinucleotides in the shifted frames; and an occurrence of four types of nucleotides in the first and second trinucleotide sites but no nucleotide G in the third trinucleotide site. Several biological consequences are presented in the Discussion. (C) 1997 Academic Press Limited.

[发布日期] 1997-12-07