|Superclasses:||Reactions Classified By Conversion Type → Simple Reactions → Chemical Reactions|
|Reactions Classified By Substrate → Small-Molecule Reactions|
EC Number: 188.8.131.52
In Pathway: sulfate activation for sulfonation
The direction shown, i.e. which substrates are on the left and right sides, is in accordance with the Enzyme Commission system.
Most BioCyc compounds have been protonated to a reference pH value of 7.3. Please see the PGDB Concepts Guide for more information.
Mass balance status: Balanced.
Enzyme Commission Primary Name: sulfate adenylyltransferase
Enzyme Commission Synonyms: adenosine-5'-triphosphate sulfurylase, adenosinetriphosphate sulfurylase, adenylylsulfate pyrophosphorylase, ATP sulfurylase, ATP-sulfurylase, sulfurylase
The first step in the activation of sulfate. The reaction occurs early in the sulfide branch of the cysteine synthesis pathway.
Enzyme Commission Summary:
The human phosphoadenosine-phosphosulfate synthase (PAPS) system is a bifunctional enzyme (fusion product of two catalytic activities). In a first step, sulfate adenylyltransferase catalyses the formation of adenosine 5′-phosphosulfate (APS) from ATP and inorganic sulfate. The second step is catalysed by the adenylylsulfate kinase portion of 3′-phosphoadenosine 5′-phosphosulfate (PAPS) synthase, which involves the formation of PAPS from enzyme-bound APS and ATP. In contrast, in bacteria, yeast, fungi and plants, the formation of PAPS is carried out by two individual polypeptides, sulfate adenylyltransferase (EC 184.108.40.206) and adenylyl-sulfate kinase ( EC 220.127.116.11).
Venkatachalam98: Venkatachalam KV, Akita H, Strott CA (1998). "Molecular cloning, expression, and characterization of human bifunctional 3'-phosphoadenosine 5'-phosphosulfate synthase and its functional domains." J Biol Chem 273(30);19311-20. PMID: 9668121
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