2a78
From Proteopedia
| |||||||
| , resolution 1.810Å | |||||||
|---|---|---|---|---|---|---|---|
| Ligands: | , | ||||||
| Gene: | RALA, RAL (Homo sapiens), C3 (Clostridium botulinum D phage) | ||||||
| Related: | 1u8y, 1u8z, 1u90, 1uad, 2bov, 1G24
| ||||||
| Resources: | FirstGlance, OCA, PDBsum, RCSB | ||||||
| Coordinates: | save as pdb, mmCIF, xml | ||||||
Crystal structure of the C3bot-RalA complex reveals a novel type of action of a bacterial exoenzyme
Overview
C3 exoenzymes from bacterial pathogens ADP-ribosylate and inactivate low-molecular-mass GTPases of the Rho subfamily. Ral, a Ras subfamily GTPase, binds the C3 exoenzymes from Clostridium botulinum and C. limosum with high affinity without being a substrate for ADP ribosylation. In the complex, the ADP-ribosyltransferase activity of C3 is blocked, while binding of NAD and NAD-glycohydrolase activity remain. Here we report the crystal structure of C3 from C. botulinum in a complex with GDP-bound RalA at 1.8 A resolution. C3 binds RalA with a helix-loop-helix motif that is adjacent to the active site. A quaternary complex with NAD suggests a mode for ADP-ribosyltransferase inhibition. Interaction of C3 with RalA occurs at a unique interface formed by the switch-II region, helix alpha3 and the P loop of the GTPase. C3-binding stabilizes the GDP-bound conformation of RalA and blocks nucleotide release. Our data indicate that C. botulinum exoenzyme C3 is a single-domain toxin with bifunctional properties targeting Rho GTPases by ADP ribosylation and Ral by a guanine nucleotide dissociation inhibitor-like effect, which blocks nucleotide exchange.
About this Structure
2A78 is a Protein complex structure of sequences from Clostridium botulinum d phage and Homo sapiens. Full crystallographic information is available from OCA.
Reference
Crystal structure of the C3bot-RalA complex reveals a novel type of action of a bacterial exoenzyme., Pautsch A, Vogelsgesang M, Trankle J, Herrmann C, Aktories K, EMBO J. 2005 Oct 19;24(20):3670-80. Epub 2005 Sep 22. PMID:16177825
Page seeded by OCA on Mon Mar 31 01:48:45 2008
