Structure of N5-carboxyaminoimidazole ribonucleotide synthase (PurK) from Bacillus anthracis
First published: 20 September 2011
L. W.-M. Fung, e-mail: [email protected]; Bernard D. Santarsiero, e-mail: [email protected]
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.
