Chorismate lyase

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In enzymology, a chorismate lyase (EC 4.1.3.40) is an enzyme that catalyzes the chemical reaction

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
chorismate 4-hydroxybenzoate + pyruvate
The chorismate pyruvate lyase (CPL) catalyzed reaction.

Hence, this enzyme has one substrate, chorismate, and two products, 4-hydroxybenzoate and pyruvate.

This enzyme 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 first step in ubiquinone biosynthesis, the removal of pyruvate from chorismate, to yield 4-hydroxybenzoate in Escherichia coli and other Gram-negative bacteria.[1] Its activity does not require metal cofactors.[2]

Activity[3][edit]

Chorismate lyase
PDB 1tt8 EBI.jpg
chorismate lyase with product, 1.0 a resolution
Identifiers
Symbol Chor_lyase
Pfam PF04345
Pfam clan CL0122
InterPro IPR007440
SCOP 1jd3
SUPERFAMILY 1jd3

Catalytic activity[edit]

  • Chorismate = 4HB + pyruvate[4]
  • This enzyme has an optimum pH at 7.5

Enzymatic activity[edit]

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[edit]

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.[1]

Nomenclature[3][edit]

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: bacteria → proteobacteria → gammaproteobacteria → enterobacteriales → enterobacteriaceae → escherichia → escherichia coli

Structure[3][edit]

This enzyme is a monomer. Its secondary structure contains helixes, turns, and beta strands.

  • It has a mass of 18,777 daltons
  • Its sequence is 165 amino acids long

Binding sites[edit]

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

Mutagenesis[3][edit]

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

References[edit]

  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. PMC 206367Freely accessible. PMID 1644758. 
  2. ^ 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. PMID 8012607. doi:10.1099/00221287-140-4-897. 
  3. ^ a b c d "UniprotID: P26602". 
  4. ^ "EC 4.1.3.40". 

Further reading[edit]

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