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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 ${\displaystyle \rightleftharpoons }$ 4-hydroxybenzoate + pyruvate

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

References

1. Nichols BP, Green JM (August 1992). "Cloning and sequencing of Escherichia coli ubiC and purification of chorismate lyase". J. Bacteriol. 174 (16): 5309–16. doi:10.1128/jb.174.16.5309-5316.1992. PMC 206367. PMID 1644758.
2. "EC 4.1.3.40".
3. Siebert M, Severin K, Heide L (April 1994). "Formation of 4-hydroxybenzoate in Escherichia coli: characterization of the ubiC gene and its encoded enzyme chorismate pyruvate-lyase". Microbiology. 140 (4): 897–904. doi:10.1099/00221287-140-4-897. PMID 8012607.
4. "KEGG PATHWAY: Ubiquinone and other terpenoid-quinone biosynthesis - Reference pathway". www.genome.jp. Retrieved 2021-04-09.
5. ^ "UniprotID: P26602".

Further reading

• Nichols BP, Green JM (1992). "Cloning and sequencing of Escherichia coli ubiC and purification of chorismate lyase". J. Bacteriol. 174 (16): 5309–16. doi:10.1128/jb.174.16.5309-5316.1992. PMC 206367. PMID 1644758.
• Siebert M, Severin K, Heide L (1994). "Formation of 4-hydroxybenzoate in Escherichia coli: characterization of the ubiC gene and its encoded enzyme chorismate pyruvate-lyase". Microbiology. 140 (4): 897–904. 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.

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