2016年1月20日 · The first structure of fully active HOIP of the RBR family of RING-type E3 ligases in its transfer complex with an E2~ubiquitin conjugate provides insights into its mechanism of action,...

2023年1月11日 · Addition of fluorescently labelled Ub (TAMRA-Ub) with a native N-terminus to GPG-Ub-loaded HOIP RBR induces the RBR aminolysis reaction, E3-Ub discharge, and formation of TAMRA-di-Ub...

Here, we show that both LUBAC catalytic activity and LUBAC specificity for linear ubiquitin chain formation are embedded within the RING‐IBR‐RING (RBR) ubiquitin ligase subunit HOIP. Linear ubiquitin chain formation by HOIP proceeds via a two‐step mechanism involving both RING and HECT E3‐type activities.

2016年1月28日 · HOIP RBR binds the E2~ubiquitin conjugate in an elongated fashion, with the E2 and E3 catalytic centres ideally aligned for ubiquitin transfer, which structurally both requires and enables a HECT-like mechanism.

2017年10月3日 · As the catalytic subunit of LUBAC, HOIP is a RING-between-RING (RBR) type E3 (Kirisako et al., 2006, Smit et al., 2012), containing mainly an N-terminal PNGase/UBA or UBX-containing protein (PUB) domain followed by a B-box type zinc finger (ZF), a canonical ZF, two Nlp4-like ZF domains (NZF1 and NZF2), a middle atypical Ub-associated domain ...

2018年5月7日 · RBR ligases are an enigmatic class of E3 ubiquitin ligases that combine properties of RING and HECT-type E3s and undergo multilevel regulation through autoinhibition, post-translational...

2014年3月3日 · The best known of the RBR enzymes are parkin, which has a prominent role in the manifestation of early-onset Parkinson's disease, and HOIP (HOIL-1-interacting protein) and HOIL-1 (haem-oxidized IRP2 ubiquitin ligase 1), both of which are components of the multiprotein LUBAC (linear ubiquitin chain assembly complex).

HOIP contains a ubiquitin-associated domain (UBA) N-terminal of the RBR core. UBA domains are small (∼45 amino acid) three-helix bundles that typically bind ubiquitin via the canonical hydrophobic surface centred on Ile44 [50].

2019年2月2日 · We report the synthesis of a diverse library of electrophilic fragments and demonstrate an integrated use of protein LC–MS, biochemical ubiquitination assays, chemical synthesis, and protein crystallography to enable the first structure-based development of covalent inhibitors for an RBR E3 ligase.

2016年1月1日 · Here we present the first structure of the fully active HOIP-RBR in its transfer complex with an E2~ubiquitin conjugate, which elucidates the intricate nature of RBR E3 ligases. The active HOIP-RBR adopts a conformation markedly different from that of autoinhibited RBRs.