6t7f
From Proteopedia
RCR E3 ligase E2-Ubiquitin transthiolation intermediate
Structural highlights
FunctionMYCB2_HUMAN E3 ubiquitin-protein ligase which mediates ubiquitination and subsequent proteasomal degradation of TSC2/tuberin. Interacts with the E2 enzymes UBE2D1, UBE2D3 and UBE2L3 (in vitro). May function as a facilitator or regulator of transcriptional activation by MYC. May have a role during synaptogenesis.[1] Publication Abstract from PubMedMYCBP2 is a ubiquitin (Ub) E3 ligase (E3) that is essential for neurodevelopment and regulates axon maintenance. MYCBP2 transfers Ub to nonlysine substrates via a newly discovered RING-Cys-Relay (RCR) mechanism, where Ub is relayed from an upstream cysteine to a downstream substrate esterification site. The molecular bases for E2-E3 Ub transfer and Ub relay are unknown. Whether these activities are linked to the neural phenotypes is also unclear. We describe the crystal structure of a covalently trapped E2~Ub:MYCBP2 transfer intermediate revealing key structural rearrangements upon E2-E3 Ub transfer and Ub relay. Our data suggest that transfer to the dynamic upstream cysteine, whilst mitigating lysine activity, requires a closed-like E2~Ub conjugate with tempered reactivity, and Ub relay is facilitated by a helix-coil transition. Furthermore, neurodevelopmental defects and delayed injury-induced degeneration in RCR-defective knock-in mice suggest its requirement, and that of substrate esterification activity, for normal neural development and programmed axon degeneration. Structural basis for RING-Cys-Relay E3 ligase activity and its role in axon integrity.,Mabbitt PD, Loreto A, Dery MA, Fletcher AJ, Stanley M, Pao KC, Wood NT, Coleman MP, Virdee S Nat Chem Biol. 2020 Nov;16(11):1227-1236. doi: 10.1038/s41589-020-0598-6. Epub, 2020 Aug 3. PMID:32747811[2] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also
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