PDBsum entry 1iap

Signaling protein

PDB id: 1iap

Contents

Protein chain

190 a.a. *

Waters ×91

* Residue conservation analysis

PDB id:

1iap

Name:

Signaling protein

Title:

Crystal structure of p115rhogef rgrgs domain

Structure:

Guanine nucleotide exchange factor p115rhogef. Chain: a. Fragment: n-terminal rgs domain. Engineered: yes

Source:

Homo sapiens. Human. Organism_taxid: 9606. Expressed in: escherichia coli bl21(de3). Expression_system_taxid: 469008.

Resolution:

1.90Å R-factor: 0.219 R-free: 0.275

Authors:

S.R.Sprang,Z.Chen

Key ref:

Z.Chen et al. (2001). Structure of the rgRGS domain of p115RhoGEF. Nat Struct Biol, 8, 805-809. PubMed id: 11524686 DOI: 10.1038/nsb0901-805

Date:

22-Mar-01 Release date: 05-Sep-01

Protein chain

Q92888  (ARHG1_HUMAN) -  Rho guanine nucleotide exchange factor 1 from Homo sapiens

Seq: 912 a.a.

Struc: 190 a.a.

Enzyme reactions

• Enzyme class: E.C.?

DOI no: 10.1038/nsb0901-805

Nat Struct Biol 8:805-809 (2001)

PubMed id: 11524686

Structure of the rgRGS domain of p115RhoGEF.

Z.Chen, C.D.Wells, P.C.Sternweis, S.R.Sprang.

ABSTRACT

p115RhoGEF, a guanine nucleotide exchange factor for Rho GTPase, is also a GTPase activating protein (GAP) for G(12) and G(13) heterotrimeric G alpha subunits. Near its N-terminus, p115RhoGEF contains a domain (rgRGS) with remote sequence identity to RGS (regulators of G protein signaling) domains. The rgRGS domain is necessary but not sufficient for the GAP activity of p115RhoGEF. The 1.9 A resolution crystal structure of the rgRGS domain shows structural similarity to RGS domains but possesses a C-terminal extension that folds into a layer of helices that pack against the hydrophobic core of the domain. Mutagenesis experiments show that rgRGS may form interactions with G alpha(13) that are analogous to those in complexes of RGS proteins with their G alpha substrates.

Selected figure(s)

Figure 1.
Figure 1. Structure of the rgRGS domain of p115RhoGEF. a, Stereo view of the C trace of the rgRGS domain. b, Representative 2F[o] - F[c] electron density, contoured at 1.5 , in the neighborhood surrounding the C-terminus of the 4 helix of p115RhoGEF. c, Ribbon diagram depicting the tertiary structure of rgRGS domain. The rgRGS domain consists of 11 helices with boundaries defined in Fig. 2b and color-coded in correspondence to their counterparts in RGS4 (ref. 11). The C-terminal four helices not present in RGS domains are colored red. Figures were prepared using Gl_render32, BOBSCRIPT33 and POV-ray34.

Figure 3.
Figure 3. A model of the rgRGS -G [13] complex. a, rgRGS domain is colored according to the scheme in Fig. 1, and G [13] is colored gray. Switch regions of G [13] are shown in plum. Residues 124 -129 in G [13] could not be modeled reliably and so were omitted from the model. b, Putative contacts between p115RhoGEF rgRGS domain and G [13] L3 - 3 and L5 segments of rgRGS are colored yellow and green, respectively; switch I and switch II of G [13] are colored plum. Side chains proposed to form specific contacts are depicted as ball-and-stick models. Oxygen, nitrogen and carbon atoms are colored red, blue and black, respectively. Putative hydrogen bonds are indicated by dotted lines. c, Structure of RGS4 -G [i1] complex11 is shown in the same orientation and color scheme. GDP, AlF[4]^- and the catalytic water molecule as bound in the active site of G [i1] are shown as ball-and-stick models.

The above figures are reprinted by permission from Macmillan Publishers Ltd: Nat Struct Biol (2001, 8, 805-809) copyright 2001.

Figures were selected by an automated process.