PMID: 26132214 , Related PDB id: 4R4L

Authors:

Qin L, Reger AS, Guo E, Yang MP, Zwart P, Casteel DE, Kim C

Title:

Structures of cGMP-Dependent Protein Kinase (PKG) Ialpha Leucine Zippers Reveal an Interchain Disulfide Bond Important for Dimer Stability.

Journal:

Biochemistry. 2015 Jul 28;54(29):4419-22. doi: 10.1021/acs.biochem.5b00572. Epub , 2015 Jul 15.

Abstract:

cGMP-dependent protein kinase (PKG) Ialpha is a central regulator of smooth muscle tone and vasorelaxation. The N-terminal leucine zipper (LZ) domain dimerizes and targets PKG Ialpha by interacting with G-kinase-anchoring proteins. The PKG Ialpha LZ contains C42 that is known to form a disulfide bond upon oxidation and to activate PKG Ialpha. To understand the molecular details of the PKG Ialpha LZ and C42-C42' disulfide bond, we determined crystal structures of the PKG Ialpha wild-type (WT) LZ and C42L LZ. Our data demonstrate that the C42-C42' disulfide bond dramatically stabilizes PKG Ialpha and that the C42L mutant mimics the oxidized WT LZ structurally.