6n84
From Proteopedia
MBP-fusion protein of transducin-alpha residues 327-350
Structural highlights
DiseaseGNAT2_HUMAN Progressive cone dystrophy;Achromatopsia. The disease is caused by variants affecting the gene represented in this entry. FunctionMALE_ECOLI Involved in the high-affinity maltose membrane transport system MalEFGK. Initial receptor for the active transport of and chemotaxis toward maltooligosaccharides.GNAT2_HUMAN Guanine nucleotide-binding proteins (G proteins) are involved as modulators or transducers in various transmembrane signaling systems. Transducin is an amplifier and one of the transducers of a visual impulse that performs the coupling between rhodopsin and cGMP-phosphodiesterase. Publication Abstract from PubMedResistance to inhibitors of cholinesterase 8A (Ric8A) is an essential regulator of G protein alpha-subunits (Galpha), acting as a guanine nucleotide exchange factor and a chaperone. We report two crystal structures of Ric8A, one in the apo form and the other in complex with a tagged C-terminal fragment of Galpha. These structures reveal two principal domains of Ric8A: an armadillo-fold core and a flexible C-terminal tail. Additionally, they show that the Galpha C-terminus binds to a highly-conserved patch on the concave surface of the Ric8A armadillo-domain, with selectivity determinants residing in the Galpha sequence. Biochemical analysis shows that the Ric8A C-terminal tail is critical for its stability and function. A model of the Ric8A/Galpha complex derived from crosslinking mass spectrometry and molecular dynamics simulations suggests that the Ric8A C-terminal tail helps organize the GTP-binding site of Galpha. This study lays the groundwork for understanding Ric8A function at the molecular level. Structural underpinnings of Ric8A function as a G-protein alpha-subunit chaperone and guanine-nucleotide exchange factor.,Srivastava D, Gakhar L, Artemyev NO Nat Commun. 2019 Jul 12;10(1):3084. doi: 10.1038/s41467-019-11088-x. PMID:31300652[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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