Biology:Chorismate lyase

Chorismate lyase
Identifiers
EC number	4.1.3.40
CAS number	157482-18-3
Databases
IntEnz	IntEnz view
BRENDA	BRENDA entry
ExPASy	NiceZyme view
KEGG	KEGG entry
MetaCyc	metabolic pathway
PRIAM	profile
PDB structures	RCSB PDB PDBe PDBsum
Search PMC articles PubMed articles NCBI proteins

The enzyme chorismate lyase (EC 4.1.3.40) catalyzes the first step in ubiquinone biosynthesis, the removal of pyruvate from chorismate, to yield 4-hydroxybenzoate in Escherichia coli and other Gram-negative bacteria. It belongs to the family of lyases, specifically the oxo-acid-lyases, which cleave carbon-carbon bonds. The systematic name of this enzyme class is chorismate pyruvate-lyase (4-hydroxybenzoate-forming). Other names in common use include CL, CPL, and UbiC.

This enzyme catalyses the chemical reaction:

chorismate [math]\displaystyle{ \rightleftharpoons }[/math] 4-hydroxybenzoate + pyruvate

File:72 2015 05 08 CPL.tif

Its activity does not require metal cofactors.

Activity

Chorismate lyase
chorismate lyase with product, 1.0 a resolution
Identifiers
Symbol	Chor_lyase
Pfam	PF04345
Pfam clan	CL0122
InterPro	IPR007440
SCOP2	1jd3 / SCOPe / SUPFAM
Available protein structures: Pfam   structures / ECOD   PDB RCSB PDB; PDBe; PDBj PDBsum structure summary

Catalytic activity

• This enzyme has an optimum pH at 7.5

Enzymatic activity

Inhibited by:

• Vanillate
• 4-hydroxybenzaldehyde
• 3-carboxylmethylaminmethyl-4-hydroxybenzoic acid
• 4HB - ubiC is inhibited by the product of the reaction, which scientists believe serves as a control mechanism for the pathway

Pathway

The pathway used is called the ubiquinone biosynthesis pathway, it catalyzes the first step in the biosynthesis of ubiquinone in E. coli. Ubiquinone is a lipid-soluble electron-transporting coenzyme. They are essential electron carriers in prokaryotes and are essential in aerobic organisms to achieve ATP synthesis.

Nomenclature

There are several different names for chorismate lyase. It is also called chorismate pyruvate lyase (4-hydroxybenzoate-forming) and it is also abbreviated several different ways: CPL, CL, and ubiC. It is sometimes referred to as ubiC, because that is the gene name. This enzyme belongs to the class lyases; more specifically the ox-acid-lyase or the carbon-carbon-lyases.

Taxonomic lineage:

1. bacteria → proteobacteria → gammaproteobacteria → enterobacteriales → enterobacteriaceae → escherichia → Escherichia coli

Structure

This enzyme is a monomer. Its secondary structure contains helixes, turns, and beta-strands. It has a mass of 18,777 daltons and its sequence is 165 amino acids long.

Binding sites

• position: 35(M)
• position: 77(R)
• position: 115(L)

Mutagenesis

• position: 91G → A; increases product inhibition by 40%. No effect on substrate affinity.
• position: 156E → K; loss of activity

Further reading

• "Cloning and sequencing of Escherichia coli ubiC and purification of chorismate lyase". J. Bacteriol. 174 (16): 5309–16. 1992. doi:10.1128/jb.174.16.5309-5316.1992. PMID 1644758. 
• "Formation of 4-hydroxybenzoate in Escherichia coli: characterization of the ubiC gene and its encoded enzyme chorismate pyruvate-lyase". Microbiology 140 (4): 897–904. 1994. doi:10.1099/00221287-140-4-897. PMID 8012607. 
• Meganathan R (2001). "Ubiquinone biosynthesis in microorganisms". FEMS Microbiol. Lett. 203 (2): 131–9. doi:10.1111/j.1574-6968.2001.tb10831.x. PMID 11583838. 

This article incorporates text from the public domain Pfam and InterPro: IPR007440