1g9q
COMPLEX STRUCTURE OF THE ADPR-ASE AND ITS SUBSTRATE ADP-RIBOSE
OverviewOverview
Regulation of cellular levels of ADP-ribose is important in preventing nonenzymatic ADP-ribosylation of proteins. The Escherichia coli ADP-ribose pyrophosphatase, a Nudix enzyme, catalyzes the hydrolysis of ADP-ribose to ribose-5-P and AMP, compounds that can be recycled as part of nucleotide metabolism. The structures of the apo enzyme, the active enzyme and the complex with ADP-ribose were determined to 1.9 A, 2.7 A and 2.3 A, respectively. The structures reveal a symmetric homodimer with two equivalent catalytic sites, each formed by residues of both monomers, requiring dimerization through domain swapping for substrate recognition and catalytic activity. The structures also suggest a role for the residues conserved in each Nudix subfamily. The Nudix motif residues, folded as a loop-helix-loop tailored for pyrophosphate hydrolysis, compose the catalytic center; residues conferring substrate specificity occur in regions of the sequence removed from the Nudix motif. This segregation of catalytic and recognition roles provides versatility to the Nudix family.
About this StructureAbout this Structure
1G9Q is a Single protein structure of sequence from Escherichia coli. Full crystallographic information is available from OCA.
ReferenceReference
The structure of ADP-ribose pyrophosphatase reveals the structural basis for the versatility of the Nudix family., Gabelli SB, Bianchet MA, Bessman MJ, Amzel LM, Nat Struct Biol. 2001 May;8(5):467-72. PMID:11323725 Page seeded by OCA on Fri May 2 17:19:26 2008