Phosphopantetheine
Encyclopedia
4'-Phosphopantetheine is an essential prosthetic group of acyl carrier protein
(ACP) and peptidyl carrier proteins (PCP) and aryl carrier proteins (ArCP) derived from Coenzyme A
. It is also present in formyltetrahydrofolate dehydrogenase
.
Acyl carrier protein
The acyl carrier protein is an important component in both fatty acid and polyketide biosynthesis with the growing chain bound during synthesis as a thiol ester at the distal thiol of a 4'-phosphopantethiene moiety...
(ACP) and peptidyl carrier proteins (PCP) and aryl carrier proteins (ArCP) derived from Coenzyme A
Coenzyme A
Coenzyme A is a coenzyme, notable for its role in the synthesis and oxidation of fatty acids, and the oxidation of pyruvate in the citric acid cycle. All sequenced genomes encode enzymes that use coenzyme A as a substrate, and around 4% of cellular enzymes use it as a substrate...
. It is also present in formyltetrahydrofolate dehydrogenase
Formyltetrahydrofolate dehydrogenase
In enzymology, a formyltetrahydrofolate dehydrogenase is an enzyme that catalyzes the chemical reactionThe 3 substrates of this enzyme are 10-formyltetrahydrofolate, NADP+, and H2O, whereas its 4 products are tetrahydrofolate, CO2, NADPH, and H+....
.
Functions
Phosphopantetheine fulfills two demands.- First, the intermediates remain covalently linked to the synthases (or synthetases) in an energy-rich thiol ester linkage.
- Second, the flexibility and length of phosphopantetheine chain (approximately 2 nm) allows the covalently tethered intermediates to have access to spatially distinct enzyme active sites.