Lys11-linked ubiquitin chains adopt compact conformations and are preferentially hydrolyzed by the deubiquitinase Cezanne

作者：Bremm Anja; Freund Stefan M V; Komander David^*

来源：Nature Structural & Molecular Biology, 2010, 17(8): 939-U47.

DOI：10.1038/nsmb.1873

Ubiquitin is a versatile cellular signaling molecule that can form polymers of eight different linkages, and individual linkage types have been associated with distinct cellular functions. Though little is currently known about Lys11-linked ubiquitin chains, recent data indicate that they may be as abundant as Lys48 linkages and may be involved in vital cellular processes. Here we report the generation of Lys11-linked polyubiquitin in vitro, for which the Lys11-specific E2 enzyme UBE2S was fused to a ubiquitin binding domain. Crystallographic and NMR analyses of Lys11-linked diubiquitin reveal that Lys11-linked chains adopt compact conformations in which Ile44 is solvent exposed. Furthermore, we identify the OTU family deubiquitinase Cezanne as the first deubiquitinase with Lys11-linkage preference. Our data highlight the intrinsic specificity of the ubiquitin system that extends to Lys11-linked chains and emphasize that differentially linked polyubiquitin chains must be regarded as independent post-translational modifications.

• 出版日期2010-8