1y3a
From Proteopedia
Structure of G-Alpha-I1 bound to a GDP-selective peptide provides insight into guanine nucleotide exchange
Structural highlights
FunctionGNAI1_HUMAN Guanine nucleotide-binding proteins (G proteins) are involved as modulators or transducers in various transmembrane signaling systems. The G(i) proteins are involved in hormonal regulation of adenylate cyclase: they inhibit the cyclase in response to beta-adrenergic stimuli. The inactive GDP-bound form prevents the association of RGS14 with centrosomes and is required for the translocation of RGS14 from the cytoplasm to the plasma membrane. May play a role in cell division.[1] [2] Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedHeterotrimeric G proteins are molecular switches that regulate numerous signaling pathways involved in cellular physiology. This characteristic is achieved by the adoption of two principal states: an inactive, GDP bound state and an active, GTP bound state. Under basal conditions, G proteins exist in the inactive, GDP bound state; thus, nucleotide exchange is crucial to the onset of signaling. Despite our understanding of G protein signaling pathways, the mechanism of nucleotide exchange remains elusive. We employed phage display technology to identify nucleotide state-dependent Galpha binding peptides. Herein, we report a GDP-selective Galpha binding peptide, KB-752, that enhances spontaneous nucleotide exchange of Galpha(i) subunits. Structural determination of the Galpha(i1)/peptide complex reveals unique changes in the Galpha switch regions predicted to enhance nucleotide exchange by creating a GDP dissociation route. Our results cast light onto a potential mechanism by which Galpha subunits adopt a conformation suitable for nucleotide exchange. Structure of Galpha(i1) bound to a GDP-selective peptide provides insight into guanine nucleotide exchange.,Johnston CA, Willard FS, Jezyk MR, Fredericks Z, Bodor ET, Jones MB, Blaesius R, Watts VJ, Harden TK, Sondek J, Ramer JK, Siderovski DP Structure. 2005 Jul;13(7):1069-80. PMID:16004878[3] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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Categories: Homo sapiens | Large Structures | Blaesius R | Bodor ET | Fredericks Z | Harden TK | Jezyk MR | Johnston CA | Jones MB | Ramer JK | Siderovski DP | Sondek J | Watts VJ | Willard FS
