8AP2

cyanide-bound [FeFe]-hydrogenase I from Clostridium pasteurianum (CpI) at 1.39 Angstrom

Summary for 8AP2

• Entry DOI: 10.2210/pdb8ap2/pdb
• Related: 4XDC
• Descriptor: Iron hydrogenase 1, IRON/SULFUR CLUSTER, FE2/S2 (INORGANIC) CLUSTER, ... (8 entities in total)
• Functional Keywords: [fefe]-hydrogenase, clostridium pasteurianum, cyanide-bound, oxidoreductase
• Biological source: Clostridium pasteurianum
• Total number of polymer chains: 2
• Total formula weight: 134634.51

Authors

Duan, J.,Hofmann, E.,Happe, T. (deposition date: 2022-08-09, release date: 2022-12-14, Last modification date: 2024-02-07)

Primary citation

Duan, J.,Hemschemeier, A.,Burr, D.J.,Stripp, S.T.,Hofmann, E.,Happe, T.
Cyanide Binding to [FeFe]-Hydrogenase Stabilizes the Alternative Configuration of the Proton Transfer Pathway.
Angew.Chem.Int.Ed.Engl., 62:e202216903-e202216903, 2023

PubMed Abstract: Hydrogenases are H converting enzymes that harbor catalytic cofactors in which iron (Fe) ions are coordinated by biologically unusual carbon monoxide (CO) and cyanide (CN ) ligands. Extrinsic CO and CN , however, inhibit hydrogenases. The mechanism by which CN binds to [FeFe]-hydrogenases is not known. Here, we obtained crystal structures of the CN -treated [FeFe]-hydrogenase CpI from Clostridium pasteurianum. The high resolution of 1.39 Å allowed us to distinguish intrinsic CN and CO ligands and to show that extrinsic CN binds to the open coordination site of the cofactor where CO is known to bind. In contrast to other inhibitors, CN treated crystals show conformational changes of conserved residues within the proton transfer pathway which could allow a direct proton transfer between E279 and S319. This configuration has been proposed to be vital for efficient proton transfer, but has never been observed structurally.

PubMed: 36464641
DOI: 10.1002/anie.202216903

Experimental method

X-RAY DIFFRACTION (1.39 Å)