2imo
Crystal structure of allantoate amidohydrolase from Escherichia coli at pH 4.6
| |||||||||||||
| 2imo, resolution 2.80Å | |||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Gene: | allC_ecoli (Escherichia coli) | ||||||||||||
| Coordinates: | save as pdb, mmCIF, xml | ||||||||||||
Overview
Purine metabolism plays a major role in regulating the availability of purine nucleotides destined for nucleic acid synthesis. Allantoate amidohydrolase catalyzes the conversion of allantoate to (S)-ureidoglycolate, one of the crucial alternate steps in purine metabolism. The crystal structure of a ternary complex of allantoate amidohydrolase with its substrate allantoate and an allosteric effector, a sulfate ion, from Escherichia coli was determined to understand better the catalytic mechanism and substrate specificity. The 2.25 A resolution X-ray structure reveals an alpha/beta scaffold akin to zinc exopeptidases of the peptidase M20 family and lacks the (beta/alpha)(8)-barrel fold characteristic of the amidohydrolases. Arrangement of the substrate and the two co-catalytic zinc ions at the active site governs catalytic specificity for hydrolysis of N-carbamyl versus the peptide bond in exopeptidases. In its crystalline form, allantoate amidohydrolase adopts a relatively open conformation. However, structural analysis reveals the possibility of a significant movement of domains via rotation about two hinge regions upon allosteric effector and substrate binding resulting in a closed catalytically competent conformation by bringing the substrate allantoate closer to co-catalytic zinc ions. Two cis-prolyl peptide bonds found on either side of the dimerization domain in close proximity to the substrate and ligand-binding sites may be involved in protein folding and in preserving the integrity of the catalytic site.
About this Structure
2IMO is a Single protein structure of sequence from Escherichia coli. Full crystallographic information is available from OCA.
Reference
Structural analysis of a ternary complex of allantoate amidohydrolase from Escherichia coli reveals its mechanics., Agarwal R, Burley SK, Swaminathan S, J Mol Biol. 2007 Apr 27;368(2):450-63. Epub 2007 Feb 20. PMID:17362992
Page seeded by OCA on Thu Mar 20 17:31:20 2008
Proteopedia Page Contributors and Editors (what is this?)
- Pages with broken file links
- Escherichia coli
- Single protein
- Agarwal, R.
- Burley, S K.
- NYSGXRC, New York Structural GenomiX Research Consortium.
- Swaminathan, S.
- Allantoate amidohydrolase
- Allc
- Apoenzyme
- New york structural genomix research consortium
- Nysgxrc
- Protein structure initiative
- Psi-2
- Structural genomic
- T1507
