title: Crystallization and preliminary X-ray characterization of the nitrile reductase QueF: a queuosine-biosynthesis enzyme.
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.
authors.affiliation: Department of Chemistry, The Skaggs Institute for Chemical Biology, The Scripps Research Institute, BCC-379, La Jolla, CA 92037, USA. swairjo@scripps.edu
authors.forename: Manal A
authors.initials: MA
authors.lastname: Swairjo
authors.forename: Robert R
authors.initials: RR
authors.lastname: Reddy
authors.forename: Bobby
authors.initials: B
authors.lastname: Lee
authors.forename: Steven G
authors.initials: SG
authors.lastname: Van Lanen
authors.forename: Shannon
authors.initials: S
authors.lastname: Brown
authors.forename: Valérie
authors.initials: V
authors.lastname: de Crécy-Lagard
authors.forename: Dirk
authors.initials: D
authors.lastname: Iwata-Reuyl
authors.forename: Paul
authors.initials: P
authors.lastname: Schimmel
mesh_terms: D001412:Bacillus subtilis / Q000201:enzymology* / Q000378:metabolism; D002384:Catalysis; D019295:Computational Biology; D003460:Crystallization; D018360:Crystallography, X-Ray / Q000379:methods*; D006136:GTP Cyclohydrolase / Q000737:chemistry; D006147:Guanine / Q000031:analogs & derivatives / Q000737:chemistry; D008956:Models, Chemical; D008958:Models, Molecular; D009249:NADP / Q000737:chemistry; D009704:Nucleoside Q / Q000737:chemistry*; D010088:Oxidoreductases / Q000737:chemistry*; D011487:Protein Conformation; D020033:Protein Isoforms; D017434:Protein Structure, Tertiary; D011744:Pyrimidinones / Q000737:chemistry; D011758:Pyrroles / Q000737:chemistry; D012323:RNA Processing, Post-Transcriptional; D012343:RNA, Transfer / Q000737:chemistry; D014961:X-Ray Diffraction
chemical_list: C096876:7-(aminomethyl)-7-deazaguanine; D020033:Protein Isoforms; D011744:Pyrimidinones; D011758:Pyrroles; D009249:NADP; D009704:Nucleoside Q; D006147:Guanine; D012343:RNA, Transfer; D010088:Oxidoreductases; D006136:GTP Cyclohydrolase; C066856:7-deazaguanine