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Crystal Structure of Human RhoA in a Dominantly Active Form Complexed with a GTP Analogue
- Source :
- Journal of Biological Chemistry. 273:9656-9666
- Publication Year :
- 1998
- Publisher :
- Elsevier BV, 1998.
-
Abstract
- The 2.4-A resolution crystal structure of a dominantly active form of the small guanosine triphosphatase (GTPase) RhoA, RhoAV14, complexed with the nonhydrolyzable GTP analogue, guanosine 5'-3-O-(thio)triphosphate (GTPgammaS), reveals a fold similar to RhoA-GDP, which has been recently reported (Wei, Y., Zhang, Y., Derewenda, U., Liu, X., Minor, W., Nakamoto, R. K., Somlyo, A. V., Somlyo, A. P., and Derewenda, Z. S. (1997) Nat. Struct. Biol. 4, 699-703), but shows large conformational differences localized in switch I and switch II. These changes produce hydrophobic patches on the molecular surface of switch I, which has been suggested to be involved in its effector binding. Compared with H-Ras and other GTPases bound to GTP or GTP analogues, the significant conformational differences are located in regions involving switches I and II and part of the antiparallel beta-sheet between switches I and II. Key residues that produce these conformational differences were identified. In addition to these differences, RhoA contains four insertion or deletion sites with an extra helical subdomain that seems to be characteristic of members of the Rho family, including Rac1, but with several variations in details. These sites also display large displacements from those of H-Ras. The ADP-ribosylation residue, Asn41, by C3-like exoenzymes stacks on the indole ring of Trp58 with a hydrogen bond to the main chain of Glu40. The recognition of the guanosine moiety of GTPgammaS by the GTPase contains water-mediated hydrogen bonds, which seem to be common in the Rho family. These structural differences provide an insight into specific interaction sites with the effectors, as well as with modulators such as guanine nucleotide exchange factor (GEF) and guanine nucleotide dissociation inhibitor (GDI).
- Subjects :
- Models, Molecular
RHOA
Protein Conformation
Stereochemistry
Molecular Sequence Data
GTPgammaS
Guanosine
GTPase
Guanosine triphosphate
Crystallography, X-Ray
Biochemistry
Protein Structure, Secondary
GTP Phosphohydrolases
chemistry.chemical_compound
GTP-binding protein regulators
GTP-Binding Proteins
Humans
Point Mutation
Computer Simulation
Amino Acid Sequence
Cloning, Molecular
Molecular Biology
Conserved Sequence
Binding Sites
Sequence Homology, Amino Acid
biology
Guanosine 5'-O-(3-Thiotriphosphate)
Cell Biology
Recombinant Proteins
chemistry
Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
Mutagenesis, Site-Directed
biology.protein
Guanosine Triphosphate
Guanine nucleotide exchange factor
rhoA GTP-Binding Protein
Sequence Alignment
Subjects
Details
- ISSN :
- 00219258
- Volume :
- 273
- Database :
- OpenAIRE
- Journal :
- Journal of Biological Chemistry
- Accession number :
- edsair.doi.dedup.....026a65b3caadde92ade48a6146c326de