7xyu | pdb_00007xyu
Crystal structure of ZER1 bound to TFLH degron
Structural highlights
FunctionZER1_HUMAN Serves as substrate adapter subunit in the E3 ubiquitin ligase complex ZYG11B-CUL2-Elongin BC (PubMed:17304241, PubMed:31273098). Acts redudantly with ZYG11B to target substrates bearing N-terminal glycine degrons for proteasomal degradation (PubMed:33093214). Involved in the clearance of proteolytic fragments generated by caspase cleavage during apoptosis since N-terminal glycine degrons are strongly enriched at caspase cleavage sites. Also important in the quality control of protein N-myristoylation in which N-terminal glycine degrons are conditionally exposed after a failure of N-myristoylation (PubMed:31273098).[1] [2] [3] Publication Abstract from PubMedN-degron pathway plays an important role in the protein quality control and maintenance of cellular protein homeostasis. ZER1 and ZYG11B, the substrate receptors of the Cullin 2-RING E3 ubiquitin ligase (CRL2), recognize N-terminal (Nt) glycine degrons and participate in the Nt-myristoylation quality control through the Gly/N-degron pathway. Here we show that ZER1 and ZYG11B can also recognize small Nt-residues other than glycine. Specifically, ZER1 binds better to Nt-Ser, -Ala, -Thr and -Cys than to -Gly, while ZYG11B prefers Nt-Gly but also has the capacity to recognize Nt-Ser, -Ala and -Cys in vitro. We found that Nt-Ser, -Ala and -Cys undergo Nt-acetylation catalyzed by Nt-acetyltransferase (NAT), thereby shielding them from recognition by ZER1/ZYG11B in cells. Instead, ZER1/ZYG11B readily targets a selection of small Nt-residues lacking Nt-acetylation for degradation in NAT-deficient cells, implicating its role in the Nt-acetylation quality control. Furthermore, we present the crystal structures of ZER1 and ZYG11B bound to various small Nt-residues and uncover the molecular mechanism of non-acetylated substrate recognition by ZER1 and ZYG11B. CRL2(ZER1/ZYG11B) recognizes small N-terminal residues for degradation.,Li Y, Zhao Y, Yan X, Ye C, Weirich S, Zhang B, Wang X, Song L, Jiang C, Jeltsch A, Dong C, Mi W Nat Commun. 2022 Dec 10;13(1):7636. doi: 10.1038/s41467-022-35169-6. PMID:36496439[4] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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