Activation process of [NiFe] hydrogenase elucidated by high-resolution X-ray analyses: conversion of the ready to the unready state

Structure. 2005 Nov;13(11):1635-42. doi: 10.1016/j.str.2005.07.018.


Hydrogenases catalyze oxidoreduction of molecular hydrogen and have potential applications for utilizing dihydrogen as an energy source. [NiFe] hydrogenase has two different oxidized states, Ni-A (unready, exhibits a lag phase in reductive activation) and Ni-B (ready). We have succeeded in converting Ni-B to Ni-A with the use of Na2S and O2 and determining the high-resolution crystal structures of both states. Ni-B possesses a monatomic nonprotein bridging ligand at the Ni-Fe active site, whereas Ni-A has a diatomic species. The terminal atom of the bridging species of Ni-A occupies a similar position as C of the exogenous CO in the CO complex (inhibited state). The common features of the enzyme structures at the unready (Ni-A) and inhibited (CO complex) states are proposed. These findings provide useful information on the design of new systems of biomimetic dihydrogen production and fuel cell devices.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Catalytic Domain
  • Crystallography, X-Ray
  • Desulfovibrio vulgaris / enzymology
  • Electron Spin Resonance Spectroscopy
  • Enzyme Activation
  • Hydrogenase / chemistry*
  • Hydrogenase / metabolism*
  • Nickel / metabolism
  • Protein Structure, Tertiary
  • Sulfides / metabolism


  • Sulfides
  • Nickel
  • nickel-iron hydrogenase
  • Hydrogenase
  • sodium sulfide

Associated data

  • PDB/1WUI
  • PDB/1WUJ
  • PDB/1WUK
  • PDB/1WUL