PDBsum entry: 1zca

Signaling protein

PDB id: 1zca

Contents

Protein chains

318 a.a. *

Ligands

ALF-GDP ×2

Metals

_MG ×2

Waters ×6

* Residue conservation analysis

PDB id:

1zca

Name:

Signaling protein

Title:

Crystal structure of g alpha 12 in complex with gdp, mg2+ and alf4-

Structure:

G alpha i/12. Chain: a, b. Fragment: n-terminal residues 1-28 of g alpha i followed by residues 49-379 of g alpha 12. Engineered: yes

Source:

Mus musculus. House mouse. Organism_taxid: 10090. Expressed in: spodoptera frugiperda. Expression_system_taxid: 7108.

Resolution:

2.90Å R-factor: 0.239 R-free: 0.296

Authors:

M.R.Nance,J.J.G.Tesmer

Key ref:

B.Kreutz et al. (2006). A new approach to producing functional G alpha subunits yields the activated and deactivated structures of G alpha(12/13) proteins. Biochemistry, 45, 167-174. PubMed id: 16388592 DOI: 10.1021/bi051729t

Date:

11-Apr-05 Release date: 15-Nov-05

Protein chains

P27600  (GNA12_MOUSE) -  Guanine nucleotide-binding protein subunit alpha-12

Seq: 379 a.a.

Struc: 318 a.a.

 Gene Ontology (GO) functional annotation 

• Biological process: signal transduction (2 terms)
• Biochemical function: signal transducer activity (3 terms)

DOI no: 10.1021/bi051729t

Biochemistry 45:167-174 (2006)

PubMed id: 16388592

A new approach to producing functional G alpha subunits yields the activated and deactivated structures of G alpha(12/13) proteins.

B.Kreutz, D.M.Yau, M.R.Nance, S.Tanabe, J.J.Tesmer, T.Kozasa.

ABSTRACT

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.