Positive and strongly relaxed purifying selection drive the evolution of repeats in proteins.

ABSTRACT: Protein repeats are considered hotspots of protein evolution, associated with acquisition of new functions and novel phenotypic traits, including disease. Paradoxically, however, repeats are often strongly conserved through long spans of evolution. To resolve this conundrum, it is necessary to directly compare paralogous (horizontal) evolution of repeats within proteins with their orthologous (vertical) evolution through speciation. Here we develop a rigorous methodology to identify highly periodic repeats with significant sequence similarity, for which evolutionary rates and selection (dN/dS) can be estimated, and systematically characterize their evolution. We show that horizontal evolution of repeats is markedly accelerated compared with their divergence from orthologues in closely rela

SUBMITTER: Persi E 

PROVIDER: S-EPMC5120217 | biostudies-literature | 2016 Nov

REPOSITORIES: biostudies-literature