Structure of the A20 Otu Domain and Mechanistic Insights Into Deubiquitination
Komander, D., Barford, D.(2008) Biochem J 409: 77
- PubMed: 17961127 
- DOI: https://doi.org/10.1042/BJ20071399
- Primary Citation of Related Structures:  
2VFJ - PubMed Abstract: 
The NF-kappaB (nuclear factor kappaB) regulator A20 antagonises IKK [IkappaB (inhibitor of kappaB) kinase] activation by modulating Lys63-linked polyubiquitination of cytokine-receptor-associated factors including TRAF2/6 (tumour-necrosis-factor-receptor-associated factor 2/6) and RIP1 (receptor-interacting protein 1). In the present paper we describe the crystal structure of the N-terminal OTU (ovarian tumour) deubiquitinase domain of A20, which differs from other deubiquitinases but shares the minimal catalytic core with otubain-2. Analysis of conserved surface regions allows prediction of ubiquitin-binding sites for the proximal and distal ubiquitin molecules. Structural and biochemical analysis suggests a novel architecture of the catalytic triad, which might be present in a subset of OTU domains including Cezanne and TRABID (TRAF-binding domain). Biochemical analysis shows a preference of the isolated A20 OTU domain for Lys48-linked tetraubiquitin in vitro suggesting that additional specificity factors might be required for the physiological function of A20 in cells.
Organizational Affiliation: 
Section of Structural Biology, The Institute of Cancer Research, Chester Beatty Laboratories, 237 Fulham Road, London SW3 6JB, UK. david.komander@icr.ac.uk