Chorismate lyase explained
| Chorismate lyase |
| Ec Number: | 4.1.3.40 |
| Cas Number: | 157482-18-3 |
The enzyme chorismate lyase 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.[1] 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:[2]
chorismate
4-hydroxybenzoate + pyruvate
Its activity does not require metal cofactors.[3]
Activity
| Symbol: | Chor_lyase |
| Chorismate lyase |
| Pfam: | PF04345 |
| Pfam Clan: | CL0122 |
| Interpro: | IPR007440 |
| Scop: | 1jd3 |
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.[4]
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.[5]
Taxonomic lineage:
- 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
- Nichols BP, Green JM . 1992 . Cloning and sequencing of Escherichia coli ubiC and purification of chorismate lyase . J. Bacteriol. . 174 . 5309 - 16 . 1644758 . 16 . 206367 . 10.1128/jb.174.16.5309-5316.1992 .
- Siebert M, Severin K, Heide L . Formation of 4-hydroxybenzoate in Escherichia coli: characterization of the ubiC gene and its encoded enzyme chorismate pyruvate-lyase . Microbiology . 140 . 897 - 904 . 8012607 . 10.1099/00221287-140-4-897 . 4 . 1994 . free .
- Meganathan R . 2001 . Ubiquinone biosynthesis in microorganisms . FEMS Microbiol. Lett. . 203 . 131 - 9 . 11583838 . 10.1111/j.1574-6968.2001.tb10831.x . 2 . free .
Notes and References
- Nichols BP, Green JM . Cloning and sequencing of Escherichia coli ubiC and purification of chorismate lyase . J. Bacteriol. . 174 . 16 . 5309–16 . August 1992 . 1644758 . 206367 . 10.1128/jb.174.16.5309-5316.1992.
- Web site: EC 4.1.3.40 .
- Siebert M, Severin K, Heide L . Formation of 4-hydroxybenzoate in Escherichia coli: characterization of the ubiC gene and its encoded enzyme chorismate pyruvate-lyase . Microbiology . 140 . 4 . 897–904 . April 1994 . 8012607 . 10.1099/00221287-140-4-897. free .
- Web site: KEGG PATHWAY: Ubiquinone and other terpenoid-quinone biosynthesis - Reference pathway. 2021-04-09. www.genome.jp.
- Web site: UniprotID: P26602 .
