4KER: Crystal Structure Of Ssopox W263v

Citation:
Abstract
Enzymes are proficient catalysts that enable fast rates of Michaelis-complex formation, the chemical step and products release. These different steps may require different conformational states of the active site that have distinct binding properties. Moreover, the conformational flexibility of the active site mediates alternative, promiscuous functions. Here we focused on the lactonase SsoPox from Sulfolobus solfataricus. SsoPox is a native lactonase endowed with promiscuous phosphotriesterase activity. We identified a position in the active site loop (W263) that governs its flexibility, and thereby affects the substrate specificity of the enzyme. We isolated two different sets of substitutions at position 263 that induce two distinct conformational sampling of the active loop and characterized the structural and kinetic effects of these substitutions. These sets of mutations selectively and distinctly mediate the improvement of the promiscuous phosphotriesterase and oxo-lactonase activities of SsoPox by increasing active-site loop flexibility. These observations corroborate the idea that conformational diversity governs enzymatic promiscuity and is a key feature of protein evolvability.
PDB ID: 4KERDownload
MMDB ID: 114115
PDB Deposition Date: 2013/4/26
Updated in MMDB: 2013/11
Experimental Method:
x-ray diffraction
Resolution: 2.6  Å
Source Organism:
Similar Structures:
Biological Unit for 4KER: dimeric; determined by author and by software (PISA)
Molecular Components in 4KER
Label Count Molecule
Proteins (2 molecules)
2
Aryldialkylphosphatase(Gene symbol: SSO_RS12240)
Molecule annotation
Chemicals (13 molecules)
1
2
2
2
3
4
4
4
5
1
* Click molecule labels to explore molecular sequence information.

Citing MMDB
.