Get   for     ? 
 Site search     ? 
Catalytic Site Atlas Version 2.2.12
Find Annotated Site: PDB code:
Swiss-Prot code:
EC number:
Help
CSA entry for 1ecm
Original Entry
Title:
Chorismate mutase
Compound:
Endo-oxabicyclic transition state analogue
Mutant:
No
UniProt/Swiss-Prot:
P07022-PHEA_ECOLI
EC Class:
4.2.1.51
5.4.99.5
Other CSA Entries:
Overview of all sites for 1ecm
Homologues of 1ecm
Entries for UniProt/Swiss-Prot: P07022
Entries for EC: 4.2.1.51
Entries for EC: 5.4.99.5
Other Databases:
PDB entry: 1ecm
PDBsum entry: 1ecm
UniProt/Swiss-Prot: P07022
IntEnz entry: 4.2.1.51
IntEnz entry: 5.4.99.5
Literature Report:
Introduction:
Chorismate mutase catalyses the intramolecular, pericyclic Claisen rearrangement of chorismate to prephenate, which is a key ion in the bacterial shikimic acid pathway, which leads to phenylalanine and tyrosine biosynthesis.
Mechanism:
The enzyme works by encouraging the substrate to adopt the conformation needed for a concerted, pericyclic reaction to occur. The two carboxylates of chorismate form bidentate electrostatic bonds with a pair of arginines (Arg 28 from one subunit and Arg 11 from the other). The arginines are specifically oriented to hold the substrate in a diaxial conformation, placing C5 and C16 adjacent, allowing for appropriate electron orbital overlap for reaction.
Sites:

Click to Display Catalytic Site (Get help with this section)
Found by:
Literature reference 

ResidueChainNumberUniProt numberFunctional part FunctionTargetDescription
ARGA 28 28Sidechain
Steric strainSubstrate
Binds to the carboxylate directly attached to the ring of chorismate, pushing the substrate into a reactive conformation.
Evidence from paper Evidence concerns Evidence type
PubMed ID 16060652 Current protein Residue is positioned appropriately (ligand position known)
PubMed ID 16060652 Current protein Computer modelling

ResidueChainNumberUniProt numberFunctional part FunctionTargetDescription
ARGB 11 11Sidechain, Backbone carbonyl
Steric strainSubstrate
Binds to the carboxylate not directly attached to the ring of chorismate, pushing the substrate into a reactive conformation.
Evidence from paper Evidence concerns Evidence type
PubMed ID 16060652 Current protein Residue is positioned appropriately (ligand position known)
PubMed ID 16060652 Current protein Computer modelling
Notes:
The hydrophobic residues Val 35 and Ile 81 act as bookends to prevent a sideways motion of the C16 and C5 reactants, but exert no pushing force on the substrate.
References:
1
A definitive mechanism for chorismate mutase.
X. Zhang and X. Zhang and T. C. Bruice
Biochemistry 44, (31) 10443-8, (2005).
16060652
Which EBI biological databases are available and how do I access them? EBI Site Map