Global pentapeptide statistics are far away from expected distributions.

ABSTRACT: The relationships between polypeptide composition, sequence, structure and function have been puzzling biologists ever since first protein sequences were determined. Here, we study the statistics of occurrence of all possible pentapeptide sequences in known proteins. To compensate for the non-uniform distribution of individual amino acid residues in protein sequences, we investigate separately all possible permutations of every given amino acid composition. For the majority of permutation groups we find that pentapeptide occurrences deviate strongly from the expected binomial distributions, and that the observed distributions are also characterized by high numbers of outlier sequences. An analysis of identified outliers shows they often contain known motifs and rare amino acids, suggesting

SUBMITTER: Poznanski J 

PROVIDER: S-EPMC6181984 | biostudies-literature | 2018 Oct

REPOSITORIES: biostudies-literature