|Superclasses:||Reactions Classified By Conversion Type → Simple Reactions → Chemical Reactions|
|Reactions Classified By Substrate → Small-Molecule Reactions|
EC Number: 18.104.22.168
In Pathway: phosphopantothenate biosynthesis III
The reaction direction shown, that is, A + B ↔ C + D versus C + D ↔ A + B, is in accordance with the direction in which it was curated.
Most BioCyc compounds have been protonated to a reference pH value of 7.3, and some reactions have been computationally balanced for hydrogen by adding free protons. Please see the PGDB Concepts Guide for more information.
Mass balance status: Balanced.
Enzyme Commission Primary Name: 4-phosphopantoate—β-alanine ligase
Enzyme Commission Synonyms: phosphopantothenate synθse, TK1686 protein
Standard Gibbs Free Energy (ΔrG'° in kcal/mol): -18.625854 [Latendresse13]
Enzyme Commission Summary:
The conversion of (R)-pantoate to (R)-4'-phosphopantothenate is part of the pathway leading to biosynthesis of 4'-phosphopantetheine, an essential cofactor of coenzyme A and acyl-carrier protein. In bacteria and eukaryotes this conversion is performed by condensation with β-alanine, followed by phosphrylation (EC 22.214.171.124 and EC 126.96.36.199, respectively). In archaea the order of these two steps is reversed, and phosphorylation precedes condensation with β-alanine. The two archaeal enzymes that catalyse this conversion are EC 188.8.131.52, pantoate kinase, and this enzyme.
Yokooji09: Yokooji Y, Tomita H, Atomi H, Imanaka T (2009). "Pantoate kinase and phosphopantothenate synthetase, two novel enzymes necessary for CoA biosynthesis in the Archaea." J Biol Chem 284(41);28137-45. PMID: 19666462
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