{"type": "root", "children": [{"type": "p", "children": [{"type": "t", "text": "\nShieldin complex subunit 3 (SHLD3) serves as the apical subunit of the shieldin complex, playing a pivotal role in DNA double-strand break repair by mediating interactions with key repair proteins. Structural studies revealed that SHLD3 contains a ladle‐shaped REV7-binding domain (RBD) composed of a conserved N-terminal loop and a less-conserved C-terminal α-helix. Crystallographic analyses at 2.2–2.3 Å resolution showed that the N-terminal loop adopts a structure similar to that found in other REV7-binding proteins, while the α-helix region uses a distinct interaction mode to bind REV7 (“safety belt” region), which is critical for retarding the dissociation of the complex."}, {"type": "fg", "children": [{"type": "fg_f", "ref": "1"}]}, {"type": "t", "text": "\n"}]}, {"type": "t", "text": "\n\n"}, {"type": "p", "children": [{"type": "t", "text": "\nIn vitro and in vivo binding assays underscored that both the N-terminal loop and the α-helix are indispensable for achieving high-affinity (low-nanomolar) binding of SHLD3 to REV7. This dual-region interaction underpins the functional role of SHLD3 in organizing the shieldin complex and facilitating efficient DNA repair through regulated REV7 engagement."}, {"type": "fg", "children": [{"type": "fg_f", "ref": "1"}]}, {"type": "t", "text": "\n"}]}, {"type": "rg", "children": [{"type": "r", "ref": 1, "children": [{"type": "t", "text": "Yaxin Dai, Fan Zhang, Longge Wang, et al. "}, {"type": "b", "children": [{"type": "t", "text": "Structural basis for shieldin complex subunit 3-mediated recruitment of the checkpoint protein REV7 during DNA double-strand break repair."}]}, {"type": "t", "text": " "}, {"type": "i", "children": [{"type": "t", "text": "J Biol Chem (2020)"}]}, {"type": "t", "text": " DOI: "}, {"type": "a", "children": [{"type": "t", "text": "10.1074/jbc.RA119.011464"}], "href": "https://doi.org/10.1074/jbc.RA119.011464"}, {"type": "t", "text": " PMID: "}, {"type": "a", "children": [{"type": "t", "text": "31796627"}], "href": "https://pubmed.ncbi.nlm.nih.gov/31796627"}]}]}]}