title: Crystal structure of cGMP-dependent protein kinase Iβ cyclic nucleotide-binding-B domain : Rp-cGMPS complex reveals an apo-like, inactive conformation.
abstract: The R-diastereomer of phosphorothioate analogs of cGMP, Rp-cGMPS, is one of few known inhibitors of cGMP-dependent protein kinase I (PKG I); however, its mechanism of inhibition is currently not fully understood. Here, we determined the crystal structure of the PKG Iβ cyclic nucleotide-binding domain (PKG Iβ CNB-B), considered a 'gatekeeper' for cGMP activation, bound to Rp-cGMPS at 1.3 Å. Our structural and NMR data show that PKG Iβ CNB-B bound to Rp-cGMPS displays an apo-like structure with its helical domain in an open conformation. Comparison with the cAMP-dependent protein kinase regulatory subunit (PKA RIα) showed that this conformation resembles the catalytic subunit-bound inhibited state of PKA RIα more closely than the apo or Rp-cAMPS-bound conformations. These results suggest that Rp-cGMPS inhibits PKG I by stabilizing the inactive conformation of CNB-B.
authors.affiliation: Structural and Computational Biology and Molecular Biophysics Program, Baylor College of Medicine, Houston, TX, USA.|Department of Pharmacology, Baylor College of Medicine, Houston, TX, USA.
authors.forename: James C
authors.initials: JC
authors.lastname: Campbell
authors.affiliation: Department of Chemistry and Chemical Biology, McMaster University, Hamilton, Canada.
authors.forename: Bryan
authors.initials: B
authors.lastname: VanSchouwen
authors.affiliation: Department of Biochemistry, University of Kassel, Kassel, Hesse, Germany.
authors.forename: Robin
authors.initials: R
authors.lastname: Lorenz
authors.affiliation: Berkeley Center for Structural Biology, Lawrence Berkeley National Laboratory, CA, USA.
authors.forename: Banumathi
authors.initials: B
authors.lastname: Sankaran
authors.affiliation: Department of Biochemistry, University of Kassel, Kassel, Hesse, Germany.
authors.forename: Friedrich W
authors.initials: FW
authors.lastname: Herberg
authors.affiliation: Department of Chemistry and Chemical Biology, McMaster University, Hamilton, Canada.
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Melacini
authors.affiliation: Structural and Computational Biology and Molecular Biophysics Program, Baylor College of Medicine, Houston, TX, USA.|Department of Pharmacology, Baylor College of Medicine, Houston, TX, USA.|Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, TX, USA.
authors.forename: Choel
authors.initials: C
authors.lastname: Kim
mesh_terms: D000595:Amino Acid Sequence; D001051:Apoenzymes / Q000737:chemistry* / Q000378:metabolism*; D018360:Crystallography, X-Ray; D006152:Cyclic GMP / Q000031:analogs & derivatives* / Q000737:chemistry / Q000378:metabolism*; D062965:Cyclic GMP-Dependent Protein Kinase Type I / Q000037:antagonists & inhibitors / Q000737:chemistry* / Q000378:metabolism*; D004795:Enzyme Stability; D007700:Kinetics; D009682:Magnetic Resonance Spectroscopy; D011487:Protein Conformation; D000072417:Protein Domains; D013237:Stereoisomerism; D013873:Thionucleotides / Q000737:chemistry / Q000378:metabolism*
chemical_list: D001051:Apoenzymes; D013873:Thionucleotides; D062965:Cyclic GMP-Dependent Protein Kinase Type I; D006152:Cyclic GMP
keywords: NO-cGMP signaling; cGMP-dependent protein kinase; kinase inhibition; second messengers