Imidazoleglycerol-phosphate dehydratase
Encyclopedia
In enzymology, an imidazoleglycerol-phosphate dehydratase is an enzyme
that catalyzes
the chemical reaction
Hence, this enzyme has one substrate
, D-erythro-1-(imidazol-4-yl)glycerol 3-phosphate, and two products
, 3-(imidazol-4-yl)-2-oxopropyl phosphate and H2O
.
This enzyme belongs to the family of lyase
s, specifically the hydro-lyases, which cleave carbon-oxygen bonds. The systematic name of this enzyme class is D-erythro-1-(imidazol-4-yl)glycerol-3-phosphate hydro-lyase [3-(imidazol-4-yl)-2-oxopropyl-phosphate-forming]. Other names in common use include IGP dehydratase, and D-erythro-1-(imidazol-4-yl)glycerol 3-phosphate hydro-lyase. This enzyme participates in histidine metabolismas it is involved in the 6th step of histidine biosynthesis as part of a nine step cyclical pathway.
IGPD is a recognised novel herbicide target as animals do not have an IGPD
There are two isoforms of IGPD; IGPD1 and IGPD2. The different isoforms are highly conserved with only 8 amino acids differing between them. These subtle differences however affect their activity but as yet it is unknown how.
is a fused imidazoleglycerol-phosphate dehydratase and histidinol-phosphatase
.
have been solved for this class of enzymes, with PDB
accession codes , , and .
Enzyme
Enzymes are proteins that catalyze chemical reactions. In enzymatic reactions, the molecules at the beginning of the process, called substrates, are converted into different molecules, called products. Almost all chemical reactions in a biological cell need enzymes in order to occur at rates...
that catalyzes
Catalysis
Catalysis is the change in rate of a chemical reaction due to the participation of a substance called a catalyst. Unlike other reagents that participate in the chemical reaction, a catalyst is not consumed by the reaction itself. A catalyst may participate in multiple chemical transformations....
the chemical reaction
Chemical reaction
A chemical reaction is a process that leads to the transformation of one set of chemical substances to another. Chemical reactions can be either spontaneous, requiring no input of energy, or non-spontaneous, typically following the input of some type of energy, such as heat, light or electricity...
- D-erythro-1-(imidazol-4-yl)glycerol 3-phosphate
3-(imidazol-4-yl)-2-oxopropyl phosphate + H2O
Hence, this enzyme has one substrate
Substrate (biochemistry)
In biochemistry, a substrate is a molecule upon which an enzyme acts. Enzymes catalyze chemical reactions involving the substrate. In the case of a single substrate, the substrate binds with the enzyme active site, and an enzyme-substrate complex is formed. The substrate is transformed into one or...
, D-erythro-1-(imidazol-4-yl)glycerol 3-phosphate, and two products
Product (chemistry)
Product are formed during chemical reactions as reagents are consumed. Products have lower energy than the reagents and are produced during the reaction according to the second law of thermodynamics. The released energy comes from changes in chemical bonds between atoms in reagent molecules and...
, 3-(imidazol-4-yl)-2-oxopropyl phosphate and H2O
Water
Water is a chemical substance with the chemical formula H2O. A water molecule contains one oxygen and two hydrogen atoms connected by covalent bonds. Water is a liquid at ambient conditions, but it often co-exists on Earth with its solid state, ice, and gaseous state . Water also exists in a...
.
This enzyme belongs to the family of lyase
Lyase
In biochemistry, a lyase is an enzyme that catalyzes the breaking of various chemical bonds by means other than hydrolysis and oxidation, often forming a new double bond or a new ring structure...
s, specifically the hydro-lyases, which cleave carbon-oxygen bonds. The systematic name of this enzyme class is D-erythro-1-(imidazol-4-yl)glycerol-3-phosphate hydro-lyase [3-(imidazol-4-yl)-2-oxopropyl-phosphate-forming]. Other names in common use include IGP dehydratase, and D-erythro-1-(imidazol-4-yl)glycerol 3-phosphate hydro-lyase. This enzyme participates in histidine metabolismas it is involved in the 6th step of histidine biosynthesis as part of a nine step cyclical pathway.
IGPD is a recognised novel herbicide target as animals do not have an IGPD
There are two isoforms of IGPD; IGPD1 and IGPD2. The different isoforms are highly conserved with only 8 amino acids differing between them. These subtle differences however affect their activity but as yet it is unknown how.
E. coli
In E. coli the enzyme encoded by the gene hisBHisB
The hisB gene, found in the enterobacteria , in Campylobacter jejuni and in Xylella/Xanthomonas encodes a protein involved in catalysis of two step in histidine biosynthesis , namely the bifunctional Imidazoleglycerol-phosphate dehydratase/histidinol-phosphatase.The former function , found at the...
is a fused imidazoleglycerol-phosphate dehydratase and histidinol-phosphatase
Histidinol-phosphatase
In enzymology, a histidinol-phosphatase is an enzyme that catalyzes the chemical reactionThus, the two substrates of this enzyme are L-histidinol phosphate and H2O, whereas its two products are L-histidinol and phosphate....
.
Structural studies
As of late 2007, 3 structuresTertiary structure
In biochemistry and molecular biology, the tertiary structure of a protein or any other macromolecule is its three-dimensional structure, as defined by the atomic coordinates.-Relationship to primary structure:...
have been solved for this class of enzymes, with PDB
Protein Data Bank
The Protein Data Bank is a repository for the 3-D structural data of large biological molecules, such as proteins and nucleic acids....
accession codes , , and .