1HH4 image
Deposition Date 2000-12-20
Release Date 2001-08-28
Last Version Date 2023-12-13
Entry Detail
PDB ID:
1HH4
Title:
Rac1-RhoGDI complex involved in NADPH oxidase activation
Biological Source:
Source Organism:
HOMO SAPIENS (Taxon ID: 9606)
Host Organism:
Method Details:
Experimental Method:
Resolution:
2.70 Å
R-Value Free:
0.28
R-Value Work:
0.25
R-Value Observed:
0.25
Space Group:
P 21 21 2
Macromolecular Entities
Polymer Type:polypeptide(L)
Molecule:RAS-RELATED C3 BOTULINUM TOXIN SUBSTRATE 1
Chain IDs:A, B
Chain Length:192
Number of Molecules:2
Biological Source:HOMO SAPIENS
Polymer Type:polypeptide(L)
Molecule:RHO GDP-DISSOCIATION INHIBITOR 1
Gene (Uniprot):ARHGDIA
Chain IDs:C (auth: D), D (auth: E)
Chain Length:204
Number of Molecules:2
Biological Source:HOMO SAPIENS
Primary Citation
Crystal Structure of the Rac1-Rhogdi Complex Involved in Nadph Oxidase Activation
Biochemistry 40 10007 ? (2001)
PMID: 11513578 DOI: 10.1021/BI010288K

Abstact

A heterodimer of prenylated Rac1 and Rho GDP dissociation inhibitor was purified and found to be competent in NADPH oxidase activation. Small angle neutron scattering experiments confirmed a 1:1 stoichiometry. The crystal structure of the Rac1-RhoGDI complex was determined at 2.7 A resolution. In this complex in which Rac1 is bound to GDP, the switch I region of Rac1 is in the GDP conformation whereas the switch II region resembles that of a GTP-bound GTPase. Two types of interaction between RhoGTPases and RhoGDI were investigated. The lipid-protein interaction between the geranylgeranyl moiety of Rac1 and RhoGDI resulted in numerous structural changes in the core of RhoGDI. The interactions between Rac1 and RhoGDI occur through hydrogen bonds which involve a number of residues of Rac1, namely, Tyr64(Rac), Arg66(Rac), His103(Rac), and His104(Rac), conserved within the Rho family and localized in the switch II region or in its close neighborhood. Moreover, in the switch II region of Rac1, hydrophobic interactions involving Leu67(Rac) and Leu70(Rac) contribute to the stability of the Rac1-RhoGDI complex. Inhibition of the GDP-GTP exchange in Rac1 upon binding to RhoGDI partly results from interaction of Thr35(Rac) with Asp45(GDI). In the Rac1-RhoGDI complex, the accessibility of the effector loops of Rac1 probably accounts for the ability of the Rac1-RhoGDI complex to activate the NADPH oxidase.

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Primary Citation of related structures