3BP1

Crystal structure of putative 7-cyano-7-deazaguanine reductase QueF from Vibrio cholerae O1 biovar eltor

Summary for 3BP1

• Entry DOI: 10.2210/pdb3bp1/pdb
• Descriptor: NADPH-dependent 7-cyano-7-deazaguanine reductase, PHOSPHATE ION, MAGNESIUM ION, ... (6 entities in total)
• Functional Keywords: alpha-beta structure, structural genomics, psi-2, protein structure initiative, midwest center for structural genomics, mcsg, oxidoreductase
• Biological source: Vibrio cholerae O1 biovar eltor str. N16961
• Total number of polymer chains: 4
• Total formula weight: 134836.15

Authors

Kim, Y.,Zhou, M.,Moy, S.,Joachimiak, A.,Midwest Center for Structural Genomics (MCSG) (deposition date: 2007-12-18, release date: 2008-01-08, Last modification date: 2024-10-16)

Primary citation

Kim, Y.,Zhou, M.,Moy, S.,Morales, J.,Cunningham, M.A.,Joachimiak, A.
High-resolution structure of the nitrile reductase QueF combined with molecular simulations provide insight into enzyme mechanism.
J.Mol.Biol., 404:127-137, 2010

PubMed Abstract: Here, we report the 1.53-Å crystal structure of the enzyme 7-cyano-7-deazaguanine reductase (QueF) from Vibrio cholerae, which is responsible for the complete reduction of a nitrile (CN) bond to a primary amine (H(2)C-NH(2)). At present, this is the only example of a biological pathway that includes reduction of a nitrile bond, establishing QueF as particularly noteworthy. The structure of the QueF monomer resembles two connected ferrodoxin-like domains that assemble into dimers. Ligands identified in the crystal structure suggest the likely binding conformation of the native substrates NADPH and 7-cyano-7-deazaguanine. We also report on a series of numerical simulations that have shed light on the mechanism by which this enzyme affects the transfer of four protons (and electrons) to the 7-cyano-7-deazaguanine substrate. In particular, the simulations suggest that the initial step of the catalytic process is the formation of a covalent adduct with the residue Cys194, in agreement with previous studies. The crystal structure also suggests that two conserved residues (His233 and Asp102) play an important role in the delivery of a fourth proton to the substrate.

PubMed: 20875425
DOI: 10.1016/j.jmb.2010.09.042

Experimental method

X-RAY DIFFRACTION (1.53 Å)