PDBsum entry: 1agr

Complex (signal transduction/regulator)

PDB id: 1agr

Contents

Protein chains

350 a.a. *

128 a.a. *

116 a.a. *

Ligands

ALF-GDP ×2

CIT ×2

Metals

_MG ×2

Waters ×58

* Residue conservation analysis

PDB id:

1agr

Name:

Complex (signal transduction/regulator)

Title:

Complex of alf4-activated gi-alpha-1 with rgs4

Structure:

Guanine nucleotide-binding protein g(i). Chain: a, d. Fragment: alpha-1. Synonym: gi-alpha-1. Engineered: yes. Rgs4. Chain: e, h. Synonym: regulator of g-protein signalling 4. Engineered: yes

Source:

Rattus norvegicus. Norway rat. Organism_taxid: 10116. Cell_line: bl21. Organ: brain. Expressed in: escherichia coli bl21(de3). Expression_system_taxid: 469008.

Biol. unit:

Monomer (from PDB file)

Resolution:

2.80Å R-factor: 0.216 R-free: 0.291

Authors:

J.J.G.Tesmer,S.R.Sprang

Key ref:

J.J.Tesmer et al. (1997). Structure of RGS4 bound to AlF4--activated G(i alpha1): stabilization of the transition state for GTP hydrolysis. Cell, 89, 251-261. PubMed id: 9108480 DOI: 10.1016/S0092-8674(00)80204-4

Date:

25-Mar-97 Release date: 16-Jun-97

Protein chains

P10824  (GNAI1_RAT) -  Guanine nucleotide-binding protein G(i) subunit alpha-1

Seq: 354 a.a.

Struc: 350 a.a.

Protein chain

P49799  (RGS4_RAT) -  Regulator of G-protein signaling 4

Seq: 205 a.a.

Struc: 128 a.a.

Protein chain

P49799  (RGS4_RAT) -  Regulator of G-protein signaling 4

Seq: 205 a.a.

Struc: 116 a.a.

 Gene Ontology (GO) functional annotation 

• Cellular component: membrane (14 terms)
• Biological process: termination of G-protein coupled receptor signaling pathway (9 terms)
• Biochemical function: nucleotide binding (9 terms)

DOI no: 10.1016/S0092-8674(00)80204-4

Cell 89:251-261 (1997)

PubMed id: 9108480

Structure of RGS4 bound to AlF4--activated G(i alpha1): stabilization of the transition state for GTP hydrolysis.

J.J.Tesmer, D.M.Berman, A.G.Gilman, S.R.Sprang.

ABSTRACT

RGS proteins are GTPase activators for heterotrimeric G proteins. We report here the 2.8 A resolution crystal structure of the RGS protein RGS4 complexed with G(i alpha1)-Mg2+-GDP-AlF4 . Only the core domain of RGS4 is visible in the crystal. The core domain binds to the three switch regions of G(i alpha1), but does not contribute catalytic residues that directly interact with either GDP or AlF4-. Therefore, RGS4 appears to catalyze rapid hydrolysis of GTP primarily by stabilizing the switch regions of G(i alpha1), although the conserved Asn-128 from RGS4 could also play a catalytic role by interacting with the hydrolytic water molecule or the side chain of Gln-204. The binding site for RGS4 on G(i alpha1) is also consistent with the activity of RGS proteins as antagonists of G(alpha) effectors.

Selected figure(s)

Figure 2.
Figure 2. The RGS4–G[iα1] Complex(A) Ribbon diagram of the RGS4–G[iα1] complex viewed from the same orientation as in Figure 1B. RGS4 is drawn with the colored segments defined in Figure 1A. The Ras-like domain of G[iα1] is drawn in dark gray, while the α-helical domain is drawn in light gray. The three switch regions of G[iα1] (residues 176–184, 201–215, and 233–241, respectively) are drawn in red. GDP–Mg^2+, bound in the active site of G[iα1], is shown as a ball-and-stick model. For clarity, AlF[4]^− is omitted from the figure.(B) Figure 2A rotated 90° around the vertical axis. RGS4 does not make significant contacts with the α-helical domain of G[iα1] and interacts almost exclusively with the switch regions of the Ras-like domain.

Figure 3.
Figure 3. Interaction Footprints of the RGS4 and G[iα1] Subunits in an “Open Book” PresentationThe G[iα1]-binding surface of RGS4 is shown in (A), and the RGS4-binding surface of G[iα1] is shown in (B). The view of the footprint in (A) corresponds to a 180° rotation around the vertical axis from the view in (B). In each case, the subunit is depicted by a predominantly purple ribbon that is colored green for residues that directly contribute to the interface. Side chains and backbone carbonyls that form contacts are drawn as ball-and-stick models. Oxygen, nitrogen, and carbon atoms are colored red, blue, and green, respectively. In (A), contacts with specific residues in G[iα1] are indicated by arrows, and the name of the contacted residue is highlighted in yellow.

The above figures are reprinted by permission from Cell Press: Cell (1997, 89, 251-261) copyright 1997.

Figures were selected by an automated process.