Actin-binding protein complexes at atomic resolution.

Abstract

This review describes three structures of actin complexed with different monomer-binding proteins, namely with DNase I, gelsolin segment 1, and profilin. In these proteins, the binding sites are discontinuous in the sequence, and those residues that form intermolecular hydrogen bonds are not well conserved in homologous proteins. The strongly conserved residues that define the family of proteins in gelsolin and profilin reflect the underlying structural fold of each. The binding surfaces for segment 1 and profilin are different, although they peripherally overlap on actin. No extreme features in the binding surfaces of these complexes distinguish them from other globular proteins.