3QC9

Crystal structure of cross-linked bovine GRK1 T8C/N480C double mutant complexed with ADP and Mg

Summary for 3QC9

• Entry DOI: 10.2210/pdb3qc9/pdb
• Descriptor: Rhodopsin kinase, ADENOSINE-5'-DIPHOSPHATE, MAGNESIUM ION, ... (5 entities in total)
• Functional Keywords: enkaryotic protein kinase fold, protein serine/threonine kinase, transferase
• Biological source: Bos taurus (bovine,cow,domestic cattle,domestic cow)
• Cellular location: Membrane; Lipid-anchor: P28327
• Total number of polymer chains: 4
• Total formula weight: 247771.48

Authors

Huang, C.-C.,Tesmer, J.J.G. (deposition date: 2011-01-15, release date: 2011-02-16, Last modification date: 2023-09-13)

Primary citation

Huang, C.C.,Orban, T.,Jastrzebska, B.,Palczewski, K.,Tesmer, J.J.
Activation of G Protein-Coupled Receptor Kinase 1 Involves Interactions between Its N-Terminal Region and Its Kinase Domain.
Biochemistry, 50:1940-1949, 2011

PubMed Abstract: G protein-coupled receptor kinases (GRKs) phosphorylate activated G protein-coupled receptors (GPCRs) to initiate receptor desensitization. In addition to the canonical phosphoacceptor site of the kinase domain, activated receptors bind to a distinct docking site that confers higher affinity and activates GRKs allosterically. Recent mutagenesis and structural studies support a model in which receptor docking activates a GRK by stabilizing the interaction of its ∼20-amino acid N-terminal region with the kinase domain. This interaction in turn stabilizes a closed, more active conformation of the enzyme. To investigate the importance of this interaction for the process of GRK activation, we first validated the functionality of the N-terminal region in rhodopsin kinase (GRK1) by site-directed mutagenesis and then introduced a disulfide bond to cross-link the N-terminal region of GRK1 with its specific binding site on the kinase domain. Characterization of the kinetic and biophysical properties of the cross-linked protein showed that disulfide bond formation greatly enhances the catalytic efficiency of the peptide phosphorylation, but receptor-dependent phosphorylation, Meta II stabilization, and inhibition of transducin activation were unaffected. These data indicate that the interaction of the N-terminal region with the kinase domain is important for GRK activation but does not dictate the affinity of GRKs for activated receptors.

PubMed: 21265573
DOI: 10.1021/bi101606e

Experimental method

X-RAY DIFFRACTION (2.7 Å)