Related Experiment Video
Updated: Jul 7, 2026

In Vitro Analysis of E3 Ubiquitin Ligase Function
Published on: May 14, 2021
The structure of the CYLD USP domain explains its specificity for Lys63-linked polyubiquitin and reveals a B box
David Komander1, Christopher J Lord, Hartmut Scheel
1Section of Structural Biology, Institute of Cancer Research, Chester Beatty Laboratories, 237 Fulham Road, London SW3 6JB, UK.
Abstract:
The tumor suppressor CYLD antagonizes NF-kappaB and JNK signaling by disassembly of Lys63-linked ubiquitin chains synthesized in response to cytokine stimulation. Here we describe the crystal structure of the CYLD USP domain, revealing a distinctive architecture that provides molecular insights into its specificity toward Lys63-linked polyubiquitin. We identify regions of the USP domain responsible for this specificity and demonstrate endodeubiquitinase activity toward such chains. Pathogenic truncations of the CYLD C terminus, associated with the hypertrophic skin tumor cylindromatosis, disrupt the USP domain, accounting for loss of CYLD catalytic activity. A small zinc-binding B box domain, similar in structure to other crossbrace Zn-binding folds--including the RING domain found in E3 ubiquitin ligases--is inserted within the globular core of the USP domain. Biochemical and functional characterization of the B box suggests a role as a protein-interaction module that contributes to determining the subcellular localization of CYLD.
Related Concept Videos
Protein Complexes with Interchangeable Parts
The SCF ubiquitin ligase is a protein complex of five individual proteins. This complex attaches ubiquitin to other target proteins to mark them for degradation. In order to...
Covalently Linked Protein Regulators
These groups modify specific amino acids in a protein.
Covalently Linked Protein Regulators
These groups modify specific amino acids in a protein.
Conserved Binding Sites
Binding sites are often located in large pockets, and if their location on a protein’s surface is unknown, it can be predicted using various approaches. The energetic method computationally analyses the...
Regulated Protein Degradation
Protein degradation plays two important roles in the cells. It helps to protect cells from misfolded or damaged proteins before they lead to a...
Intralumenal Vesicles and Multivesicular Bodies

