Crystallization and preliminary X-ray characterization of the nitrile reductase QueF: a queuosine-biosynthesis enzyme

Acta Crystallogr Sect F Struct Biol Cryst Commun. 2005 Oct 1;61(Pt 10):945-8. doi: 10.1107/S1744309105029246. Epub 2005 Sep 30.

Abstract

QueF (MW = 19.4 kDa) is a recently characterized nitrile oxidoreductase which catalyzes the NADPH-dependent reduction of 7-cyano-7-deazaguanine (preQ0) to 7-aminomethyl-7-deazaguanine, a late step in the biosynthesis of the modified tRNA nucleoside queuosine. Initial crystals of homododecameric Bacillus subtilis QueF diffracted poorly to 8.0 A. A three-dimensional model based on homology with the tunnel-fold enzyme GTP cyclohydrolase I suggested catalysis at intersubunit interfaces and a potential role for substrate binding in quaternary structure stabilization. Guided by this insight, a second crystal form was grown that was strictly dependent on the presence of preQ0. This crystal form diffracted to 2.25 A resolution.

Publication types

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

MeSH terms

  • Bacillus subtilis / enzymology*
  • Bacillus subtilis / metabolism
  • Catalysis
  • Computational Biology
  • Crystallization
  • Crystallography, X-Ray / methods*
  • GTP Cyclohydrolase / chemistry
  • Guanine / analogs & derivatives
  • Guanine / chemistry
  • Models, Chemical
  • Models, Molecular
  • NADP / chemistry
  • Nucleoside Q / chemistry*
  • Oxidoreductases / chemistry*
  • Protein Conformation
  • Protein Isoforms
  • Protein Structure, Tertiary
  • Pyrimidinones / chemistry
  • Pyrroles / chemistry
  • RNA Processing, Post-Transcriptional
  • RNA, Transfer / chemistry
  • X-Ray Diffraction

Substances

  • 7-(aminomethyl)-7-deazaguanine
  • Protein Isoforms
  • Pyrimidinones
  • Pyrroles
  • NADP
  • Nucleoside Q
  • Guanine
  • RNA, Transfer
  • Oxidoreductases
  • GTP Cyclohydrolase
  • 7-deazaguanine