Journal article
Crystal structure of cGMP-dependent protein kinase Ibeta cyclic nucleotide-binding-B domain: Rp-cGMPS complex reveals an apo-like, inactive conformation
Publication Details
Authors: | Campbell, J.; Van Schouwen, B.; Lorenz, R.; Sankaran, B.; Herberg, F.; Melacini, G.; Kim, C. |
Publication year: | 2017 |
Journal: | FEBS Letters |
Pages range : | 221-230 |
Volume number: | 591 |
Issue number: | 1 |
ISSN: | 0014-5793 |
DOI-Link der Erstveröffentlichung: |
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 Ibeta cyclic nucleotide-binding domain (PKG Ibeta CNB-B), considered a 'gatekeeper' for cGMP activation, bound to Rp-cGMPS at 1.3 A. Our structural and NMR data show that PKG Ibeta 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 RIalpha) showed that this conformation resembles the catalytic subunit-bound inhibited state of PKA RIalpha 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.
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 Ibeta cyclic nucleotide-binding domain (PKG Ibeta CNB-B), considered a 'gatekeeper' for cGMP activation, bound to Rp-cGMPS at 1.3 A. Our structural and NMR data show that PKG Ibeta 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 RIalpha) showed that this conformation resembles the catalytic subunit-bound inhibited state of PKA RIalpha 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.
Keywords
Amino Acid Sequence, Apoenzymes, Apoenzymes/chemistry/metabolism, Cyclic GMP/analogs & derivatives/chemistry/metabolism, Cyclic GMP-Dependent Protein Kinase Type I/antagonists & inhibitors/chemistry/metabolism, EC 2.7.11.12 (Cyclic GMP-Dependent Protein Kinase Type I, Enzyme Stability, H2D2X058MU (Cyclic GMP, Kinetics, Magnetic Resonance Spectroscopy, Protein Conformation, Protein Domains, Stereoisomerism, Thionucleotides, Thionucleotides/chemistry/metabolism
