EVOLUTIONARY CLUSTERING AND FUNCTIONAL SIMILARITY OF RNA-BINDING PROTEINS

RNA-binding proteins (RNPs) involved in splicing, processing and trans lation regulation contain one to four RNA-binding domains. We construc ted a phylogenetic tree for the RNA-binding domains, including those o f poly(A)-binding protein (PABP), splicing factors, chloroplast RNPs, hnRNPs, snRNP U1-70K, nucleolin and Drosophila sex determinants. Prote ins with similar functions were found to have closely related RNA-bind ing domains and common domain organizations. In light of these observa tion, one can assume the function of an RNA-binding protein, based on the evolutionary relationship between its RNA-binding domain(s) and do main organization, as compared with other RNPs.