PDBsum entry 1p6c

Hydrolase

PDB id: 1p6c

Contents

Protein chains

331 a.a. *

Ligands

EBP ×2

DII ×2

Metals

_ZN ×4

Waters ×321

* Residue conservation analysis

PDB id:

1p6c

Name:

Hydrolase

Title:

Crystal structure of phosphotriesterase triple mutant h254g/h257w/l303t complexed with diisopropylmethylphosphonate

Structure:

Parathion hydrolase. Chain: a, b. Synonym: phosphotriesterase, pte. Engineered: yes. Mutation: yes

Source:

Flavobacterium sp.. Organism_taxid: 239. Gene: opd. Expressed in: escherichia coli. Expression_system_taxid: 562.

Biol. unit:

Dimer (from PQS)

Resolution:

2.00Å R-factor: 0.185 R-free: 0.246

Authors:

C.M.Hill,W.Li,J.B.Thoden,H.M.Holden,F.M.Raushel

Key ref:

C.M.Hill et al. (2003). Enhanced degradation of chemical warfare agents through molecular engineering of the phosphotriesterase active site. J Am Chem Soc, 125, 8990-8991. PubMed id: 15369336 DOI: 10.1021/ja0358798

Date:

29-Apr-03 Release date: 16-Sep-03

Protein chains

P0A433  (OPD_SPHSA) -  Parathion hydrolase from Sphingobium fuliginis (strain ATCC 27551)

Seq: 365 a.a.

Struc: 331 a.a.*

* PDB and UniProt seqs differ at 4 residue positions (black crosses)

Enzyme reactions

• Enzyme class: E.C.3.1.8.1 - aryldialkylphosphatase.
• Reaction: An aryl dialkyl phosphate + H2O = dialkyl phosphate + an aryl alcohol

aryl dialkyl phosphate (Bound ligand (Het Group name = DII) matches with 41.18% similarity) + H2O = dialkyl phosphate + aryl alcohol

• Cofactor: Divalent cation

Molecule diagrams generated from .mol files obtained from the KEGG ftp site

Added reference

DOI no: 10.1021/ja0358798

J Am Chem Soc 125:8990-8991 (2003)

PubMed id: 15369336

Enhanced degradation of chemical warfare agents through molecular engineering of the phosphotriesterase active site.

C.M.Hill, W.S.Li, J.B.Thoden, H.M.Holden, F.M.Raushel.

ABSTRACT

The bacterial phosphotriesterase has been utilized as a template for the evolution of improved enzymes for the catalytic decomposition of organophosphate nerve agents. A combinatorial library of active site mutants was constructed by randomizing residues His-254, His-257, and Leu-303. The collection of mutant proteins was screened for the ability to hydrolyze a chromogenic analogue of the most toxic stereoisomer of the chemical warfare agent, soman. The mutant H254G/H257W/L303T catalyzed the hydrolysis of the target substrate nearly 3 orders of magnitude faster than the wild-type enzyme. The X-ray crystal structure was solved in the presence and absence of diisopropyl methyl phosphonate. The mutant enzyme was ligated to an additional divalent cation at the active site that was displaced upon the binding of the substrate analogue inhibitor. These studies demonstrate that substantial changes in substrate specificity can be achieved by relatively minor changes to the primary amino acid sequence.