Crystallization and preliminary X-ray characterization of the nitrile reductase QueF: a queuosine-biosynthesis enzyme.
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.
Swairjo
Manal A
MA
Department of Chemistry, The Skaggs Institute for Chemical Biology, The Scripps Research Institute, BCC-379, La Jolla, CA 92037, USA. swairjo@scripps.edu
Reddy
Robert R
RR
Lee
Bobby
B
Van Lanen
Steven G
SG
Brown
Shannon
S
de Crécy-Lagard
Valérie
V
Iwata-Reuyl
Dirk
D
Schimmel
Paul
P
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
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