Structure determination of an FMN reductase from Pseudomonas aeruginosa PA01 using sulfur anomalous signal.
The availability of high-intensity synchrotron facilities, technological advances in data-collection techniques and improved data-reduction and crystallographic software have ushered in a new era in high-throughput macromolecular crystallography. Here, the de novo automated crystal structure determination at 1.28 A resolution of an NAD(P)H-dependent FMN reductase flavoprotein from Pseudomonas aeruginosa PA01-derived protein Q9I4D4 using the anomalous signal from an unusually small number of S atoms is reported. Although this protein lacks the flavodoxin key fingerprint motif [(T/S)XTGXT], it has been confirmed to bind flavin mononucleotide and the binding site was identified via X-ray crystallography. This protein contains a novel flavin mononucleotide-binding site GSLRSGSYN, which has not been previously reported. Detailed statistics pertaining to sulfur phasing and other factors contributing to structure determination are discussed. Structural comparisons of the apoenzyme and the protein complexed with flavin mononucleotide show conformational changes on cofactor binding. NADPH-dependent activity has been confirmed with biochemical assays.
Biology Department, Brookhaven National Laboratory, Upton, NY 11973, USA.
Rakhi
R
Agarwal
Jeffrey B
JB
Bonanno
Stephen K
SK
Burley
Subramanyam
S
Swaminathan
D000595:Amino Acid Sequence; D001665:Binding Sites; D002384:Catalysis; D003067:Coenzymes / Q000737:chemistry; D003460:Crystallization; D018360:Crystallography, X-Ray / Q000379:methods; D019281:Dimerization; D001330:Electronic Data Processing; D038181:FMN Reductase / Q000737:chemistry* / Q000235:genetics; D005486:Flavin Mononucleotide / Q000737:chemistry; D008958:Models, Molecular; D008969:Molecular Sequence Data; D009249:NADP / Q000737:chemistry; D017434:Protein Structure, Tertiary; D011550:Pseudomonas aeruginosa / Q000201:enzymology* / Q000235:genetics; D011994:Recombinant Proteins / Q000737:chemistry; D017386:Sequence Homology, Amino Acid; D040681:Structural Homology, Protein; D013455:Sulfur / Q000737:chemistry*
D003067:Coenzymes; D011994:Recombinant Proteins; D009249:NADP; D013455:Sulfur; D005486:Flavin Mononucleotide; D038181:FMN Reductase