Strictosidine synthase
Encyclopedia
Strictosidine synthase a key enzyme in alkaloid
biosynthesis. It catalyses the condensation of tryptamine
with secologanin
to form strictosidine:
Thus, the two substrates
of this enzyme are 3-alpha(S)-strictosidine and H2O
, whereas its two products
are tryptamine
and secologanin
.
This enzyme belongs to the family of lyase
s, specifically amine lyases, which cleave carbon-nitrogen bonds. The systematic name of this enzyme class is 3-alpha(S)-strictosidine tryptamine-lyase (secologanin-forming). Other names in common use include strictosidine synthetase, STR, and 3-alpha(S)-strictosidine tryptamine-lyase. This enzyme participates in terpenoid biosynthesis and indole and ipecac alkaloid biosynthesis.
have been solved for this class of enzymes, with PDB
accession codes , , , and .
Alkaloid
Alkaloids are a group of naturally occurring chemical compounds that contain mostly basic nitrogen atoms. This group also includes some related compounds with neutral and even weakly acidic properties. Also some synthetic compounds of similar structure are attributed to alkaloids...
biosynthesis. It catalyses the condensation of tryptamine
Tryptamine
Tryptamine is a monoamine alkaloid found in plants, fungi, and animals. It is based around the indole ring structure, and is chemically related to the amino acid tryptophan, from which its name is derived...
with secologanin
Secologanin
Secologanin is a monoterpene synthesized from geranyl pyrophosphate in the mevalonate pathway. Secologanin then proceedes with dopamine to form ipecac alkaloids.-Biosynthesis:...
to form strictosidine:
- 3-alpha(S)-strictosidine + H2O
tryptamine + secologanin
Thus, the two substrates
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...
of this enzyme are 3-alpha(S)-strictosidine 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...
, whereas its 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...
are tryptamine
Tryptamine
Tryptamine is a monoamine alkaloid found in plants, fungi, and animals. It is based around the indole ring structure, and is chemically related to the amino acid tryptophan, from which its name is derived...
and secologanin
Secologanin
Secologanin is a monoterpene synthesized from geranyl pyrophosphate in the mevalonate pathway. Secologanin then proceedes with dopamine to form ipecac alkaloids.-Biosynthesis:...
.
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 amine lyases, which cleave carbon-nitrogen bonds. The systematic name of this enzyme class is 3-alpha(S)-strictosidine tryptamine-lyase (secologanin-forming). Other names in common use include strictosidine synthetase, STR, and 3-alpha(S)-strictosidine tryptamine-lyase. This enzyme participates in terpenoid biosynthesis and indole and ipecac alkaloid biosynthesis.
Structural studies
As of late 2007, 4 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 .