Database accession: MF7000165
Name: Isochorismate-pyruvate lyase, K42E mutant (Pseudomonas aeruginosa)
PDB ID: 3ret
Experimental method: X-ray (1.79 Å)
Assembly: Homodimer
Source organism: Pseudomonas aeruginosa
Primary publication of the structure:
Olucha J, Ouellette AN, Luo Q, Lamb AL
pH Dependence of catalysis by Pseudomonas aeruginosa isochorismate-pyruvate lyase: implications for transition state stabilization and the role of lysine 42.
(2011) Biochemistry 50: 7198-207
PMID: 21751784
Abstract:
An isochorismate-pyruvate lyase with adventitious chorismate mutase activity from Pseudomonas aerugionsa (PchB) achieves catalysis of both pericyclic reactions in part by the stabilization of reactive conformations and in part by electrostatic transition-state stabilization. When the active site loop Lys42 is mutated to histidine, the enzyme develops a pH dependence corresponding to a loss of catalytic power upon deprotonation of the histidine. Structural data indicate that the change is not due to changes in active site architecture, but due to the difference in charge at this key site. With loss of the positive charge on the K42H side chain at high pH, the enzyme retains lyase activity at ∼100-fold lowered catalytic efficiency but loses detectable mutase activity. We propose that both substrate organization and electrostatic transition state stabilization contribute to catalysis. However, the dominant reaction path for catalysis is dependent on reaction conditions, which influence the electrostatic properties of the enzyme active site amino acid side chains.
Annotations from the GeneOntology database. Only terms that fit at least two of the interacting proteins are shown. Molecular function:
carbon-oxygen lyase activity carbon-oxygen lyase activity
chorismate mutase activity chorismate mutase activity
isochorismate pyruvate lyase activity isochorismate pyruvate lyase activity
Biological process:
chorismate metabolic process chorismate metabolic process
pyochelin biosynthetic process pyochelin biosynthetic process
salicylic acid biosynthetic process salicylic acid biosynthetic process
Cellular component: not assigned
Structural annotations of the participating protein chains.Entry contents: 2 distinct polypeptide molecules
Chains: A, B
Notes: All chains according to the most probable oligomerization state stored in PDBe were considered.
Number of unique protein segments: 1
Name: Isochorismate pyruvate lyase
Source organism: Pseudomonas aeruginosa
Length: 101 residues
Sequence:Sequence according to the corresponding UniProt protein segmentMKTPEDCTGLADIREAIDRIDLDIVQALGRRMDYVKAASRFKASEAAIPAPERVAAMLPERARWAEENGLDAPFVEGLFAQIIHWYIAEQIKYWRQTRGAA
UniProtKB AC: Q51507 (positions: 1-97)
Coverage: 96%
Name: Isochorismate pyruvate lyase
Source organism: Pseudomonas aeruginosa
Length: 101 residues
Sequence:Sequence according to the corresponding UniProt protein segmentMKTPEDCTGLADIREAIDRIDLDIVQALGRRMDYVKAASRFKASEAAIPAPERVAAMLPERARWAEENGLDAPFVEGLFAQIIHWYIAEQIKYWRQTRGAA
UniProtKB AC: Q51507 (positions: 1-97)
Coverage: 96%
Evidence demonstrating that the participating proteins are unstructured prior to the interaction and their folding is coupled to binding. Representative domain in related structures: Chorismate mutase type II
Evidence level: Indirect evidence
Evidence coverage: The full structure participates in mutual synergistic folding.
Complex Evidence:
The enzyme is an intertwined dimer of three helices with connecting loops. The N-terminal helices of the two monomers twine together to form an anti-parallel coiled-coil with a hydrophobic interaction surface. The loop between the first and second helices is disordered (PMID:16914555).
Chain A:
N/A
Chain B:
N/A
Surface and contacts features:
Structures from the PDB that contain the same number of proteins, and the proteins from the two structures show a sufficient degree of pairwise similarity, i.e. they belong to the same UniRef90 cluster (the full proteins exhibit at least 90% sequence identity) and convey roughly the same region to their respective interactions (the two regions from the two proteins share a minimum of 70% overlap). Download the CIF file (.cif)
Download this entry's XML file (.xml)
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