Mutations at the hydrophobic core affect Hal3 trimer stability, reducing its Ppz1 inhibitory capacity but not its PPCDC moonlighting function.

ABSTRACT: S. cerevisiae Hal3 (ScHal3) is a moonlighting protein that, is in its monomeric state, regulates the Ser/Thr protein phosphatase Ppz1, but also joins ScCab3 (and in some instances the Hal3 paralog Vhs3) to form an unusual heterotrimeric phosphopantothenoylcysteine decarboxylase (PPCDC) enzyme. PPCDC is required for CoA biosynthesis and in most eukaryotes is a homotrimeric complex with three identical catalytic sites at the trimer interfaces. However, in S. cerevisiae the heterotrimeric arrangement results in a single functional catalytic center. Importantly, the specific structural determinants that direct Hal3's oligomeric state and those required for Ppz1 inhibition remain largely unknown. We mutagenized residues in the predicted hydrophobic core of ScHal3 (L403-L405) and the plant Arabi

SUBMITTER: Santolaria C 

PROVIDER: S-EPMC6168597 | biostudies-literature | 2018 Oct

REPOSITORIES: biostudies-literature