Experimentally Reconstruction of Protein Structural Evolution

Abstract

Proteins involved in the central dogma frequently contain small β-barrel structures with different folds, such as DPBB conserved in RNA polymerases and RIFT, OB, and SH3 conserved in ribosomal proteins. Although previous studies have suggested the ancestral form and evolutionary relationships between these β-barrel folds based on their partial sequence and structural similarities, no experimental evidence has been provided until recently. Recent studies reconstructed a putative ancestral DPBB protein with a simplified sequence and experimentally confirmed that it can be converted to different β-barrel folds. These experiments imply that the four β-barrel folds evolved from a common ancestral protein through the intermediary fold, DZBB.