Phosphopantothenate-cysteine ligase

In enzymology, a phosphopantothenate-cysteine ligase is an enzyme that catalyzes the chemical reaction


 * CTP + (R)-4'-phosphopantothenate + L-cysteine $$\rightleftharpoons$$ CMP + diphosphate + N-[(R)-4'-phosphopantothenoyl]-L-cysteine

The 3 substrates of this enzyme are CTP, (R)-4'-phosphopantothenate, and L-cysteine, whereas its 3 products are CMP, diphosphate, and N-[(R)-4'-phosphopantothenoyl]-L-cysteine.

This enzyme belongs to the family of ligases, specifically those forming carbon-nitrogen bonds as acid-D-amino-acid ligases (peptide synthases). The systematic name of this enzyme class is (R)-4'-phosphopantothenate:L-cysteine ligase. This enzyme is also called phosphopantothenoylcysteine synthetase. This enzyme participates in pantothenate and coa biosynthesis.

Structural studies
As of late 2007, 5 structures have been solved for this class of enzymes, with PDB accession codes, , , , and.