This old version of Proteopedia is provided for student assignments while the new version is undergoing repairs. Content and edits done in this old version of Proteopedia after March 1, 2026 will eventually be lost when it is retired in about June of 2026.
Apply for new accounts at the new Proteopedia. Your logins will work in both the old and new versions.
1zca
From Proteopedia
|
Crystal structure of G alpha 12 in complex with GDP, Mg2+ and AlF4-
Overview
The oncogenic G(12/13) subfamily of heterotrimeric G proteins transduces extracellular signals that regulate the actin cytoskeleton, cell cycle progression, and gene transcription. Previously, structural analyses of fully functional G alpha(12/13) subunits have been hindered by insufficient amounts of homogeneous, functional protein. Herein, we report that substitution of the N-terminal helix of G alpha(i1) for the corresponding region of G alpha12 or G alpha13 generated soluble chimeric subunits (G alpha(i/12) and G alpha(i/13)) that could be purified in sufficient amounts for crystallographic studies. Each chimera bound guanine nucleotides, G betagamma subunits, and effector proteins and exhibited GAP responses to p115RhoGEF and leukemia-associated RhoGEF. Like their wild-type counterparts, G alpha(i/13), but not G alpha(i/12), stimulated the activity of p115RhoGEF. Crystal structures of the G alpha(i/12) x GDP x AlF4(-) and G alpha(i/13) x GDP complexes were determined using diffraction data extending to 2.9 and 2.0 A, respectively. These structures reveal not only the native structural features of G alpha12 and G alpha13 subunits, which are expected to be important for their interactions with GPCRs and effectors such as G alpha-regulated RhoGEFs, but also novel conformational changes that are likely coupled to GTP hydrolysis in the G alpha(12/13) class of heterotrimeric G proteins.
About this Structure
1ZCA is a Single protein structure of sequence from Mus musculus with , and as ligands. Full crystallographic information is available from OCA.
Reference
A new approach to producing functional G alpha subunits yields the activated and deactivated structures of G alpha(12/13) proteins., Kreutz B, Yau DM, Nance MR, Tanabe S, Tesmer JJ, Kozasa T, Biochemistry. 2006 Jan 10;45(1):167-74. PMID:16388592
Page seeded by OCA on Thu Feb 21 16:14:08 2008
Categories: Mus musculus | Single protein | Nance, M R. | Tesmer, J J.G. | ALF | GDP | MG | Gtp-binding | Lipoprotein | Membrane | Palmitate | Transducer
