title: Structure of N5-carboxyaminoimidazole ribonucleotide synthase (PurK) from Bacillus anthracis.
abstract: The apo structure of N5-carboxyaminoimidazole ribonucleotide synthase (PurK) from Bacillus anthracis (baPurK) with Mg2+ in the active site is reported at 1.96 Å resolution. PurK is an enzyme in the purine-biosynthetic pathway, unique to prokaryotes, that converts 5-aminoimidazole ribonucleotide to N5-carboxyaminoimidazole ribonucleotide and has been suggested as a potential antimicrobial drug target. Two interesting features of baPurK are a flexible B-loop (residues 149/150-157) that is in close contact with the active site and the binding of Mg2+ to the active site without additional ligands.
authors.affiliation: Department of Chemistry, University of Illinois at Chicago, Chicago, IL 60607, USA.
authors.forename: Micheal L
authors.initials: ML
authors.lastname: Tuntland
authors.forename: Michael E
authors.initials: ME
authors.lastname: Johnson
authors.forename: L W-M
authors.initials: LW
authors.lastname: Fung
authors.forename: Bernard D
authors.initials: BD
authors.lastname: Santarsiero
mesh_terms: D001408:Bacillus anthracis / Q000201:enzymology*; D001426:Bacterial Proteins / Q000737:chemistry; D001665:Binding Sites; D020134:Catalytic Domain; D018360:Crystallography, X-Ray; D007093:Imidazoles / Q000378:metabolism; D008025:Ligases / Q000737:chemistry* / Q000378:metabolism; D008274:Magnesium / Q000378:metabolism; D011487:Protein Conformation
chemical_list: D001426:Bacterial Proteins; D007093:Imidazoles; C098330:4-aminoimidazole; D008025:Ligases; D008274:Magnesium