The X-ray crystal structure of Shewanella oneidensis OmcA reveals new insight at the microbe-mineral interface

The X-ray crystal structure of Shewanella oneidensis OmcA, an extracellular decaheme cytochrome involved in mineral reduction, was solved to a resolution of 2.7 angstrom. The four OmcA molecules in the asymmetric unit are arranged so the minimum distance between heme 5 on adjacent OmcA monomers is 9 angstrom, indicative of a transient OmcA dimer capable of intermolecular electron transfer. A previously identified hematite binding motif was identified near heme 10, forming a hydroxylated surface that would bring a heme 10 electron egress site to similar to 10 degrees of a mineral surface. Structured summary of protein interactions: OmcA and OmcA bind by X-ray crystallography (View interaction) (C) 2014 Federation of European Biochemical Societies. Published by Elsevier B. V. All rights reserved.