InterPro domain: IPR035929

CoaB adopts a 3-layer alpha/beta/alpha fold with mixed beta-sheets, which topologically resembles a combination of Rossmann-like and ribokinase-like folds. This structural domain can be found in human phosphopantothenoylcysteine (PPC) synthetase [ 1 ] and CoaB from the Escherichia coli coenzyme A bifunctional protein CoaBC [ 2 ]. The structure of these proteins predicts a ping pong mechanism with initial formation of an acyladenylate intermediate, followed by release of pyrophosphate and attack by cysteine to form the final products PPC and AMP.

1. Structure of human phosphopantothenoylcysteine synthetase at 2.3 A resolution. Structure 11, 927-36
2. Structural basis of CTP-dependent peptide bond formation in coenzyme A biosynthesis catalyzed by Escherichia coli PPC synthetase. Structure 12, 1977-88