4KEU

Crystal structure of SsoPox W263M

Summary for 4KEU

• Entry DOI: 10.2210/pdb4keu/pdb
• Related: 2VC5 2VC7 3UF9 4KER 4KES 4KET 4KEV 4KEZ 4KF1
• Descriptor: Aryldialkylphosphatase, FE (II) ION, COBALT (II) ION, ... (6 entities in total)
• Functional Keywords: (beta/alpha)8-hydrolase, lactonase, hydrolase
• Biological source: Sulfolobus solfataricus
• Total number of polymer chains: 4
• Total formula weight: 143733.58

Authors

Gotthard, G.,Hiblot, J.,Chabriere, E.,Elias, M. (deposition date: 2013-04-26, release date: 2013-10-02, Last modification date: 2025-03-26)

Primary citation

Hiblot, J.,Gotthard, G.,Elias, M.,Chabriere, E.
Differential Active Site Loop Conformations Mediate Promiscuous Activities in the Lactonase SsoPox.
Plos One, 8:e75272-e75272, 2013

PubMed 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.

PubMed: 24086491
DOI: 10.1371/journal.pone.0075272

Experimental method

X-RAY DIFFRACTION (2.2 Å)