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5udh
From Proteopedia
HHARI/ARIH1-UBCH7~Ubiquitin
Structural highlights
Function[ARI1_HUMAN] E3 ubiquitin-protein ligase, which catalyzes polyubiquitination of target proteins together with ubiquitin-conjugating enzyme E2 UBE2L3. May play a role in protein translation by mediating polyubiquitination of EIF4E2, leading to its subsequent degradation.[1] [2] [3] [UB2L3_HUMAN] Ubiquitin-conjugating enzyme E2 that specifically acts with HECT-type and RBR family E3 ubiquitin-protein ligases. Does not function with most RING-containing E3 ubiquitin-protein ligases because it lacks intrinsic E3-independent reactivity with lysine: in contrast, it has activity with the RBR family E3 enzymes, such as PARK2 and ARIH1, that function like function like RING-HECT hybrids. Accepts ubiquitin from the E1 complex and catalyzes its covalent attachment to other proteins. In vitro catalyzes 'Lys-11'-linked polyubiquitination. Involved in the selective degradation of short-lived and abnormal proteins. Down-regulated during the S-phase it is involved in progression through the cell cycle. Regulates nuclear hormone receptors transcriptional activity. May play a role in myelopoiesis.[4] [5] [6] [7] [8] [9] [10] Publication Abstract from PubMedRING-between-RING (RBR) E3s contain RING1 domains that are structurally similar yet mechanistically distinct from canonical RING domains. Both types of E3 bind E2 approximately ubiquitin (E2 approximately Ub) via their RINGs but canonical RING E3s promote closed E2 approximately Ub conformations required for direct Ub transfer from the E2 to substrate, while RBR RING1s promote open E2 approximately Ub to favor Ub transfer to the E3 active site. This different RING/E2 approximately Ub conformation determines its direct target, which for canonical RING E3s is typically a substrate or substrate-linked Ub, but is the E3 active-site cysteine in the case of RBR-type E3s. Here we show that a short extension of HHARI RING1, namely Zn2+-loop II, not present in any RING E3s, acts as a steric wedge to disrupt closed E2 approximately Ub, providing a structural explanation for the distinctive RING1-dependent conformational restriction mechanism utilized by RBR E3s. Structural Studies of HHARI/UbcH7 approximately Ub Reveal Unique E2 approximately Ub Conformational Restriction by RBR RING1.,Dove KK, Olszewski JL, Martino L, Duda DM, Wu XS, Miller DJ, Reiter KH, Rittinger K, Schulman BA, Klevit RE Structure. 2017 Jun 6;25(6):890-900.e5. doi: 10.1016/j.str.2017.04.013. Epub 2017, May 25. PMID:28552575[11] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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