PDBsum entry 1f7c

Signaling protein

PDB id: 1f7c

Contents

Protein chain

182 a.a. *

Waters ×47

* Residue conservation analysis

PDB id:

1f7c

Name:

Signaling protein

Title:

Crystal structure of the bh domain from graf, the gtpase regulator associated with focal adhesion kinase

Structure:

Rhogap protein. Chain: a. Fragment: gtpase activating protein (gap) for rho family gtpases. Engineered: yes

Source:

Gallus gallus. Chicken. Organism_taxid: 9031. Expressed in: escherichia coli. Expression_system_taxid: 562.

Resolution:

2.40Å R-factor: 0.205 R-free: 0.252

Authors:

K.L.Longenecker,U.Derewenda,P.J.Sheffield,Y.Zheng,Z.S.Derewenda

Key ref:

K.L.Longenecker et al. (2000). Structure of the BH domain from graf and its implications for Rho GTPase recognition. J Biol Chem, 275, 38605-38610. PubMed id: 10982819 DOI: 10.1074/jbc.M007574200

Date:

26-Jun-00 Release date: 20-Dec-00

Protein chain

Q5ZMW5  (RHG26_CHICK) -  Rho GTPase-activating protein 26 from Gallus gallus

Seq: 760 a.a.

Struc: 182 a.a.

Enzyme reactions

• Enzyme class: E.C.?

DOI no: 10.1074/jbc.M007574200

J Biol Chem 275:38605-38610 (2000)

PubMed id: 10982819

Structure of the BH domain from graf and its implications for Rho GTPase recognition.

K.L.Longenecker, B.Zhang, U.Derewenda, P.J.Sheffield, Z.Dauter, J.T.Parsons, Y.Zheng, Z.S.Derewenda.

ABSTRACT

Cellular signaling by small G-proteins is down-regulated by GTPase-activating proteins (GAPs), which increase the rate of GTP hydrolysis. The GTPase regulator associated with focal adhesion kinase (Graf) exhibits GAP activity toward the RhoA and Cdc42 GTPases, but is only weakly active toward the closely related Rac1. We determined the crystal structure of a 231-residue fragment of Graf (GrafGAP), a domain containing the GAP activity, at 2.4-A resolution. The structure clarifies the boundaries of the functional domain and yields insight to the mechanism of substrate recognition. Modeling its interaction with substrate suggested that a favorable interaction with Glu-95 of Cdc42 (Glu-97 of RhoA) would be absent with the corresponding Ala-95 of Rac1. Indeed, GrafGAP activity is diminished approximately 40-fold toward a Cdc42 E95A mutant, whereas a approximately 10-fold increase is observed for a Rac1 A95E mutant. The GrafGAP epitope that apparently interacts with Glu-95(Glu-97) contains Asn-225, which was recently found mutated in some myeloid leukemia patients. We conclude that position 95 of the GTPase is an important determinant for GrafGAP specificity in cellular function and tumor suppression.

Selected figure(s)

Figure 1.
Fig. 1. Structure of GrafGAP. A, this stereo view of the final 2F[o] F[c] map, contoured at 1.0 , shows the electron density of Leu-193, which stabilizes the N-terminal boundary of the BH domain. B, the ribbon drawing colored from the N terminus (blue) to C terminus (red) illustrates the overall fold of GrafGAP. Secondary elements are labeled as for structures of BH[PI3-K] and p50RhoGAP (7, 26). This figure was prepared with BOBSCRIPT (27).

Figure 4.
Fig. 4. Amino acid type at position 95 of Cdc42 or Rac1 is an important determinant for GrafGAP activity. The relative sensitivity of 5 µM Rho GTPases to activation were measured in the absence ( open bars) or presence of 50 nM GrafGAP (dashed bars) or 200 nM GrafGAP (double-dashed bars) by the nitrocellulose filter binding assay.

The above figures are reprinted by permission from the ASBMB: J Biol Chem (2000, 275, 38605-38610) copyright 2000.

Figures were selected by an automated process.