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

FEBS Lett. 2014 May 21;588(10):1886-90. doi: 10.1016/j.febslet.2014.04.013. Epub 2014 Apr 18.

Abstract

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 Å. The four OmcA molecules in the asymmetric unit are arranged so the minimum distance between heme 5 on adjacent OmcA monomers is 9 Å, 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 ∼10 Å of a mineral surface.

Keywords: Electron transfer; Metalloprotein; Mineral respiration; Multiheme cytochrome; Outer membrane; Shewanella; c-Type heme.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Amino Acid Sequence
  • Bacterial Outer Membrane Proteins / chemistry*
  • Bacterial Outer Membrane Proteins / genetics
  • Bacterial Outer Membrane Proteins / metabolism
  • Binding Sites / genetics
  • Crystallography, X-Ray
  • Heme / chemistry
  • Heme / metabolism
  • Hydroxylation
  • Models, Molecular
  • Molecular Sequence Data
  • Protein Multimerization*
  • Protein Structure, Tertiary*
  • Scattering, Small Angle
  • Sequence Homology, Amino Acid
  • Shewanella / genetics
  • Shewanella / metabolism*
  • X-Ray Diffraction

Substances

  • Bacterial Outer Membrane Proteins
  • Heme