7AJK

Crystal structure of CRYI-B Rac1 complex

This is a non-PDB format compatible entry.

Summary for 7AJK

• Entry DOI: 10.2210/pdb7ajk/pdb
• Descriptor: Ras-related C3 botulinum toxin substrate 1, CYFIP-related Rac1 interactor B, MAGNESIUM ION, ... (5 entities in total)
• Functional Keywords: actin, cytoskeleton, rac1, gtpase, inhibitor, cytosolic protein
• Biological source: Homo sapiens (Human); More
• Total number of polymer chains: 2
• Total formula weight: 57232.29

Authors

Yelland, T.,Anh, L.,Insall, R.,Machesky, L.,Ismail, S. (deposition date: 2020-09-29, release date: 2020-11-18, Last modification date: 2024-01-31)

Primary citation

Yelland, T.,Le, A.H.,Nikolaou, S.,Insall, R.,Machesky, L.,Ismail, S.
Structural Basis of CYRI-B Direct Competition with Scar/WAVE Complex for Rac1.
Structure, 29:226-237.e4, 2021

PubMed Abstract: Rac1 is a major regulator of actin dynamics, with GTP-bound Rac1 promoting actin assembly via the Scar/WAVE complex. CYRI competes with Scar/WAVE for interaction with Rac1 in a feedback loop regulating actin dynamics. Here, we reveal the nature of the CYRI-Rac1 interaction, through crystal structures of CYRI-B lacking the N-terminal helix (CYRI-BΔN) and the CYRI-BΔN:Rac1Q61L complex, providing the molecular basis for CYRI-B regulation of the Scar/WAVE complex. We reveal CYRI-B as having two subdomains - an N-terminal Rac1 binding subdomain with a unique Rac1-effector interface and a C-terminal Ratchet subdomain that undergoes conformational changes induced by Rac1 binding. Finally, we show that the CYRI protein family, CYRI-A and CYRI-B can produce an autoinhibited hetero- or homodimers, adding an additional layer of regulation to Rac1 signaling.

PubMed: 33217330
DOI: 10.1016/j.str.2020.11.003

Experimental method

X-RAY DIFFRACTION (3.1 Å)