Jump to content

User:PU2017rgonza/sandbox

From Wikipedia, the free encyclopedia
Anthranilate Synthase 1i1q
3D Rendering of Anthranilate Synthase
Identifiers
EC no.4.1.3.27
CAS no.9031-59-8
Databases
IntEnzIntEnz view
BRENDABRENDA entry
ExPASyNiceZyme view
KEGGKEGG entry
MetaCycmetabolic pathway
PRIAMprofile
PDB structuresRCSB PDB PDBe PDBsum
Gene OntologyAmiGO / QuickGO
Search
PMCarticles
PubMedarticles
NCBIproteins

In enzymology, an anthranilate synthase (EC 4.1.3.27) is an enzyme that catalyzes the chemical reaction

chorismate + L-glutamine anthranilate + pyruvate + L-glutamate 2

Thus, the two substrates of this enzyme are chorismate and L-glutamine, whereas its 3 products are anthranilate, pyruvate, and L-glutamate.

Function[edit]

Chorismate is a precursor in plants for at least four metabolic pathways. These four pathways lead to the formation of Trp, Phe/Tyr, salicylate/phylloquinone, and folate. The four enzymes that compete for are CM, anthranilate synthase (AS), isochorismate synthase (ICS), and aminodeoxychorismate synthase (ADCS) each catalyzing for their respective pathway.

The AS enzyme is allosterically inhibited by tryptophan, which binds to AS∝ preventing conformational change. This suggests that AS∝ is responsible for feedback inhibition by tryptophan.]

Reaction[edit]

Anthranilate synthase (EC 4.1.3.27) is an enzyme that catalyzes the chemical reaction

chorismate + L-glutamine anthranilate + pyruvate + L-glutamate
Alt text
Chemical equation of reaction occurring in anthranilate synthase

.

Thus, the two substrates of this enzyme are chorismate and L-glutamine, whereas its 3 products are anthranilate, pyruvate, and L-glutamate.

[AS∝ binds to chorismate and catalyzes the amination and pyruvate elimination reaction whereas ASβ hydrolyzes glutamine and provides ammonia to AS∝. The binding of chorismate to AS∝ triggers a conformational change to an active state and creates an intermolecular channel for ammonia transfer from ASβ to AS∝.]

Homologues[edit]

This enzyme is found in a number of eukaryotic species including saccharomyces cerevisiae, kluyveromyces lactis, schizosaccharomyces pombe, magnaporthe oryzae, neurospora crassa, arabidopsis thaliana, and oryza sativa.[1]

Structure[edit]

Anthranilate synthase is made up of a large alpha and small beta subunits capable of forming alpha/beta heterodimers or an a2/b2 tetramer.

Nomenclature[edit]

This enzyme belongs to the family of lyases, to be specifica the oxo-acid-lyases, which cleave carbon-carbon bonds. The systematic name of this enzyme class is chorismate pyruvate-lyase (amino-accepting; anthranilate-forming). Other names in common use include

  • anthranilate synthetase
  • chorismate lyase
  • chorismate pyruvate-lyase (amino-accepting).

This enzyme participates in phenylalanine, tyrosine and tryptophan biosynthesis and two-component system - general.

Structural studies[edit]

As of late 2007, 5 structures have been solved for this class of enzymes, with PDB accession codes 1I1Q, 1I7Q, 1I7S, 1QDL, and 2I6Y.

Application[edit]

References[edit]

  1. ^ "Gene".

Category:EC 4.1.3 Category:Enzymes of known structure Category:Anthranilates