PSI protein classifier: A new program automating PSI-BLAST search results

A new program, PSI Protein Classifier, generalizing the results of both successive and independent iterations of the PSI-BLAST program was developed. The technical opportunities of the program are described and illustrated by two examples. An iterative screening of the amino acid sequence database detected potential evolutionary relationships between GH5, GH13, GH27, GH31, GH36, GH66, GH101 and GH114 families of glycoside hydrolases. Analysis of the statistically significant sequence similarity (E-value analysis) allowed us to divide the family GH31 into 38 subfamilies.