6K08

Crystal structure of REV7(R124A/A135D) in complex with a Shieldin3 fragment

Summary for 6K08

• Entry DOI: 10.2210/pdb6k08/pdb
• Descriptor: Mitotic spindle assembly checkpoint protein MAD2B, Shieldin complex subunit 3, SULFATE ION, ... (4 entities in total)
• Functional Keywords: dsb repair complex, gene regulation, transcription-protein binding complex, transcription/protein binding
• Biological source: Homo sapiens (Human); More
• Total number of polymer chains: 2
• Total formula weight: 28694.18

Authors

Zhang, F.,Dai, Y. (deposition date: 2019-05-05, release date: 2019-12-11, Last modification date: 2023-11-22)

Primary citation

Dai, Y.,Zhang, F.,Wang, L.,Shan, S.,Gong, Z.,Zhou, Z.
Structural basis for shieldin complex subunit 3-mediated recruitment of the checkpoint protein REV7 during DNA double-strand break repair.
J.Biol.Chem., 295:250-262, 2020

PubMed Abstract: Shieldin complex subunit 3 (SHLD3) is the apical subunit of a recently-identified shieldin complex and plays a critical role in DNA double-strand break repair. To fulfill its function in DNA repair, SHLD3 interacts with the mitotic spindle assembly checkpoint protein REV7 homolog (REV7), but the details of this interaction remain obscure. Here, we present the crystal structures of REV7 in complex with SHLD3's REV7-binding domain (RBD) at 2.2-2.3 Å resolutions. The structures revealed that the ladle-shaped RBD in SHLD3 uses its N-terminal loop and C-terminal α-helix (αC-helix) in its interaction with REV7. The N-terminal loop exhibited a structure similar to those previously identified in other REV7-binding proteins, and the less-conserved αC-helix region adopted a distinct mode for binding REV7. and binding analyses revealed that the N-terminal loop and the αC-helix are both indispensable for high-affinity REV7 binding (with low-nanomolar affinity), underscoring the crucial role of SHLD3 αC-helix in protein binding. Moreover, binding kinetics analyses revealed that the REV7 "safety belt" region, which plays a role in binding other proteins, is essential for SHLD3-REV7 binding, as this region retards the dissociation of the RBD from the bound REV7. Together, the findings of our study reveal the molecular basis of the SHLD3-REV7 interaction and provide critical insights into how SHLD3 recognizes REV7.

PubMed: 31796627
DOI: 10.1074/jbc.RA119.011464

Experimental method

X-RAY DIFFRACTION (2.312 Å)