Phosphoribosylaminoimidazolesuccinocarboxamide synthase
Encyclopedia
In enzymology, a phosphoribosylaminoimidazolesuccinocarboxamide synthase is an enzyme
that catalyzes
the chemical reaction
The 3 substrates
of this enzyme are ATP
, 5-amino-1-(5-phospho-D-ribosyl)imidazole-4-carboxylate, and L-aspartate, whereas its 4 products
are ADP
, phosphate
, (S)-2-[5-amino-1-(5-phospho-D-ribosyl)imidazole-4-, and carboxamido]succinate.
This enzyme belongs to the family of ligase
s, to be specific those forming carbon-nitrogen bonds as acid-D-amino-acid ligases (peptide synthases). The systematic name of this enzyme class is 5-amino-1-(5-phospho-D-ribosyl)imidazole-4-carboxylate:L-aspartate ligase (ADP-forming). Other names in common use include phosphoribosylaminoimidazole-succinocarboxamide synthetase, PurC, SAICAR synthetase, 4-(N-succinocarboxamide)-5-aminoimidazole synthetase, 4-[(N-succinylamino)carbonyl]-5-aminoimidazole ribonucleotide, synthetase, SAICARs, phosphoribosylaminoimidazolesuccinocarboxamide synthetase, and 5-aminoimidazole-4-N-succinocarboxamide ribonucleotide synthetase. This enzyme participates in purine metabolism
.
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...
- ATP + 5-amino-1-(5-phospho-D-ribosyl)imidazole-4-carboxylate + L-aspartate ADP + phosphate + (S)-2-[5-amino-1-(5-phospho-D-ribosyl)imidazole-4- carboxamido]succinate
The 3 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 ATP
Adenosine triphosphate
Adenosine-5'-triphosphate is a multifunctional nucleoside triphosphate used in cells as a coenzyme. It is often called the "molecular unit of currency" of intracellular energy transfer. ATP transports chemical energy within cells for metabolism...
, 5-amino-1-(5-phospho-D-ribosyl)imidazole-4-carboxylate, and L-aspartate, whereas its 4 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 ADP
Adenosine diphosphate
Adenosine diphosphate, abbreviated ADP, is a nucleoside diphosphate. It is an ester of pyrophosphoric acid with the nucleoside adenosine. ADP consists of the pyrophosphate group, the pentose sugar ribose, and the nucleobase adenine....
, phosphate
Phosphate
A phosphate, an inorganic chemical, is a salt of phosphoric acid. In organic chemistry, a phosphate, or organophosphate, is an ester of phosphoric acid. Organic phosphates are important in biochemistry and biogeochemistry or ecology. Inorganic phosphates are mined to obtain phosphorus for use in...
, (S)-2-[5-amino-1-(5-phospho-D-ribosyl)imidazole-4-, and carboxamido]succinate.
This enzyme belongs to the family of ligase
Ligase
In biochemistry, ligase is an enzyme that can catalyse the joining of two large molecules by forming a new chemical bond, usually with accompanying hydrolysis of a small chemical group dependent to one of the larger molecules...
s, to be specific those forming carbon-nitrogen bonds as acid-D-amino-acid ligases (peptide synthases). The systematic name of this enzyme class is 5-amino-1-(5-phospho-D-ribosyl)imidazole-4-carboxylate:L-aspartate ligase (ADP-forming). Other names in common use include phosphoribosylaminoimidazole-succinocarboxamide synthetase, PurC, SAICAR synthetase, 4-(N-succinocarboxamide)-5-aminoimidazole synthetase, 4-[(N-succinylamino)carbonyl]-5-aminoimidazole ribonucleotide, synthetase, SAICARs, phosphoribosylaminoimidazolesuccinocarboxamide synthetase, and 5-aminoimidazole-4-N-succinocarboxamide ribonucleotide synthetase. This enzyme participates in purine metabolism
Purine metabolism
-Biosynthesis:Purines are biologically synthesized as nucleotides and in particular as ribotides, i.e. bases attached to ribose 5-phosphate. A key regulatory step is the production of 5-phospho-α-D-ribosyl 1-pyrophosphate by PRPP synthetase, which is activated by inorganic phosphate and...
.
Structural studies
As of late 2007, 10 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 .