The HydG enzyme generates an Fe(CO)2(CN) synthon in assembly of the FeFe hydrogenase H-cluster

Science. 2014 Jan 24;343(6169):424-7. doi: 10.1126/science.1246572.

Abstract

Three iron-sulfur proteins--HydE, HydF, and HydG--play a key role in the synthesis of the [2Fe](H) component of the catalytic H-cluster of FeFe hydrogenase. The radical S-adenosyl-L-methionine enzyme HydG lyses free tyrosine to produce p-cresol and the CO and CN(-) ligands of the [2Fe](H) cluster. Here, we applied stopped-flow Fourier transform infrared and electron-nuclear double resonance spectroscopies to probe the formation of HydG-bound Fe-containing species bearing CO and CN(-) ligands with spectroscopic signatures that evolve on the 1- to 1000-second time scale. Through study of the (13)C, (15)N, and (57)Fe isotopologs of these intermediates and products, we identify the final HydG-bound species as an organometallic Fe(CO)2(CN) synthon that is ultimately transferred to apohydrogenase to form the [2Fe](H) component of the H-cluster.

Publication types

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

MeSH terms

  • Bacterial Proteins / chemistry*
  • Catalysis
  • Catalytic Domain*
  • Hydrogenase / chemistry*
  • Iron Carbonyl Compounds / metabolism*
  • Iron-Sulfur Proteins / chemistry*
  • Shewanella putrefaciens / enzymology
  • Spectroscopy, Fourier Transform Infrared

Substances

  • Bacterial Proteins
  • Iron-Sulfur Proteins
  • Iron Carbonyl Compounds
  • iron hydrogenase
  • Hydrogenase