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Simplified amino acid alphabets based on deviation of conditional probability from random background

Biological Physics 2009-11-07 v1 Data Analysis, Statistics and Probability q-bio

Abstract

The primitive data for deducing the Miyazawa-Jernigan contact energy or BLOSUM score matrix consists of pair frequency counts. Each amino acid corresponds to a conditional probability distribution. Based on the deviation of such conditional probability from random background, a scheme for reduction of amino acid alphabet is proposed. It is observed that evident discrepancy exists between reduced alphabets obtained from raw data of the Miyazawa-Jernigan's and BLOSUM's residue pair counts. Taking homologous sequence database SCOP40 as a test set, we detect homology with the obtained coarse-grained substitution matrices. It is verified that the reduced alphabets obtained well preserve information contained in the original 20-letter alphabet.

Cite

@article{arxiv.physics/0211031,
  title  = {Simplified amino acid alphabets based on deviation of conditional probability from random background},
  author = {Xin Liu and Di Liu and Ji Qi and Wei-Mou Zheng},
  journal= {arXiv preprint arXiv:physics/0211031},
  year   = {2009}
}

Comments

9 pages,3figures