Tuyển tập báo cáo các nghiên cứu khoa học quốc tế ngành hóa học dành cho các bạn yêu hóa học tham khảo đề tài: Research Article Splitting the BLOSUM Score into Numbers of Biological Significance | Hindawi Publishing Corporation EURASIP Journal on Bioinformatics and Systems Biology Volume 2007 Article ID 31450 18 pages doi 2007 31450 Research Article Splitting the BLOSUM Score into Numbers of Biological Significance Francesco Fabris 1 2 Andrea Sgarro 1 2 and Alessandro Tossi3 1 Dipartimento di Matematica e Informatica Universita degli Studi di Trieste via Valerio 12b 34127 Trieste Italy 2 Centro di Biomedicina Molecolare AREA Science Park Strada Statale 14 Basovizza 34012 Trieste Italy 3 Dipartimento di Biochimica Biofisica e Chimica delle Macromolecole Universita degli Studi di Trieste via Licio Giorgieri 1 34127 Trieste Italy Received 2 October 2006 Accepted 30 March 2007 Recommended by Juho Rousu Mathematical tools developed in the context of Shannon information theory were used to analyze the meaning of the BLOSUM score which was split into three components termed as the BLOSUM spectrum or BLOSpectrum . These relate respectively to the sequence convergence the stochastic similarity of the two protein sequences to the background frequency divergence typicality of the amino acid probability distribution in each sequence and to the target frequency divergence compliance of the amino acid variations between the two sequences to the protein model implicit in the BLOCKS database . This treatment sharpens the protein sequence comparison providing a rationale for the biological significance of the obtained score and helps to identify weakly related sequences. Moreover the BLOSpectrum can guide the choice of the most appropriate scoring matrix tailoring it to the evolutionary divergence associated with the two sequences or indicate if a compositionally adjusted matrix could perform better. Copyright 2007 Francesco Fabris et al. This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use distribution and reproduction in any medium provided the original work is properly cited. 1. INTRODUCTION .
