6X1G

Crystal structure of a GEF domain from the Orientia tsutsugamushi protein OtDUB in complex with Rac1

Summary for 6X1G

• Entry DOI: 10.2210/pdb6x1g/pdb
• Descriptor: ULP_PROTEASE domain-containing protein, Ras-related C3 botulinum toxin substrate 1, MAGNESIUM ION, ... (4 entities in total)
• Functional Keywords: guanine nucleotide exchange factor, gef, rac1, gtpase, orientia tsutsugamushi, scrub typhus, signaling protein, signaling protein-hydrolase complex, signaling protein/hydrolase
• Biological source: Orientia tsutsugamushi (Rickettsia tsutsugamushi); More
• Total number of polymer chains: 4
• Total formula weight: 91484.66

Authors

Lim, C.S.,Xiong, Y. (deposition date: 2020-05-18, release date: 2020-11-25, Last modification date: 2023-10-18)

Primary citation

Lim, C.,Berk, J.M.,Blaise, A.,Bircher, J.,Koleske, A.J.,Hochstrasser, M.,Xiong, Y.
Crystal structure of a guanine nucleotide exchange factor encoded by the scrub typhus pathogen Orientia tsutsugamushi .
Proc.Natl.Acad.Sci.USA, 117:30380-30390, 2020

PubMed Abstract: Rho family GTPases regulate an array of cellular processes and are often modulated by pathogens to promote infection. Here, we identify a cryptic guanine nucleotide exchange factor (GEF) domain in the OtDUB protein encoded by the pathogenic bacterium A proteomics-based OtDUB interaction screen identified numerous potential host interactors, including the Rho GTPases Rac1 and Cdc42. We discovered a domain in OtDUB with Rac1/Cdc42 GEF activity (OtDUB), with higher activity toward Rac1 in vitro. While this GEF bears no obvious sequence similarity to known GEFs, crystal structures of OtDUB alone (3.0 Å) and complexed with Rac1 (1.7 Å) reveal striking convergent evolution, with a unique topology, on a V-shaped bacterial GEF fold shared with other bacterial GEF domains. Structure-guided mutational analyses identified residues critical for activity and a mechanism for nucleotide displacement. Ectopic expression of OtDUB activates Rac1 preferentially in cells, and expression of the OtDUB alone alters cell morphology. Cumulatively, this work reveals a bacterial GEF within the multifunctional OtDUB that co-opts host Rac1 signaling to induce changes in cytoskeletal structure.

PubMed: 33184172
DOI: 10.1073/pnas.2018163117

Experimental method

X-RAY DIFFRACTION (1.6 Å)