Olzhausen J, Moritz T, Neetz T, Schueller HJ

Coenzyme A (CoA) as an essential cofactor for acyl and acetyl transfer reactions is synthesized in five enzymatic steps from pantothenate, cysteine and ATP. In the yeast S. cerevisiae, products of five essential genes CAB1-CAB5 (coenzyme A biosynthesis) are required to catalyze CoA biosynthesis. In addition, non-essential genes SIS2 and ...

Read More

VHS3 similar to CAB3 are also involved. Using epitope-tagged variants of Cab3 and Cab5 we show that both proteins cofractionate upon chromatographic separation, forming a complex of ~ 330 kDa. We thus systematically investigated interactions among Cab proteins. Our results show that Cab2, Cab3, Cab4 and Cab5 indeed bind to each other, with Cab3 as the sole protein which can interact with itself and other Cab proteins. Cab3 also binds to Sis2 and Vhs3 which were previously characterized as subunits of phosphopantothenoylcysteine decarboxylase. Pantothenate kinase encoded by CAB1 as the rate-limiting enzyme of CoA biosynthesis did not interact with other Cab proteins. Mapping studies revealed that the nonconserved N-terminus of Cab3 is required for dimerization and for binding of Cab2 and Cab5. Our interaction studies confirm early reports on the existence of a CoA-synthesizing protein complex (CoA-SPC) in yeast and provide precise data on protein domains involved in complex formation. This article is protected by copyright. All rights reserved.

Date: Jun. 22, 2013

View in: Pubmed Google Scholar

156282