OTUB1 co-opts Lys48-linked ubiquitin recognition to suppress E2 enzyme function.
Ubiquitylation entails the concerted action of E1, E2, and E3 enzymes. We recently reported that OTUB1, a deubiquitylase, inhibits the DNA damage response independently of its isopeptidase activity. OTUB1 does so by blocking ubiquitin transfer by UBC13, the cognate E2 enzyme for RNF168. OTUB1 also inhibits E2s of the UBE2D and UBE2E families. Here we elucidate the structural mechanism by which OTUB1 binds E2s to inhibit ubiquitin transfer. OTUB1 recognizes ubiquitin-charged E2s through contacts with both donor ubiquitin and the E2 enzyme. Surprisingly, free ubiquitin associates with the canonical distal ubiquitin-binding site on OTUB1 to promote formation of the inhibited E2 complex. Lys48 of donor ubiquitin lies near the OTUB1 catalytic site and the C terminus of free ubiquitin, a configuration that mimics the products of Lys48-linked ubiquitin chain cleavage. OTUB1 therefore co-opts Lys48-linked ubiquitin chain recognition to suppress ubiquitin conjugation and the DNA damage response.
Samuel Lunenfeld Research Institute, Mount Sinai Hospital, Toronto, ON M5G 1X5, Canada.
Yu-Chi
YC
Juang
Marie-Claude
MC
Landry
Mario
M
Sanches
Vinayak
V
Vittal
Charles C Y
CC
Leung
Derek F
DF
Ceccarelli
Abigail-Rachele F
AR
Mateo
Jonathan N
JN
Pruneda
Daniel Y L
DY
Mao
Rachel K
RK
Szilard
Stephen
S
Orlicky
Meagan
M
Munro
Peter S
PS
Brzovic
Rachel E
RE
Klevit
Frank
F
Sicheri
Daniel
D
Durocher
D019943:Amino Acid Substitution; D002460:Cell Line; D018360:Crystallography, X-Ray; D003546:Cysteine Endopeptidases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D000072017:Deubiquitinating Enzymes; D006801:Humans; D007700:Kinetics; D008958:Models, Molecular; D016297:Mutagenesis, Site-Directed; D030781:Organisms, Genetically Modified; D011485:Protein Binding; D054730:Protein Interaction Domains and Motifs; D020836:Protein Structure, Quaternary; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism; D025801:Ubiquitin / Q000737:chemistry / Q000378:metabolism; D044763:Ubiquitin-Conjugating Enzymes / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D057149:Ubiquitinated Proteins / Q000378:metabolism*; D054875:Ubiquitination; D015003:Yeasts / Q000235:genetics / Q000254:growth & development
D011994:Recombinant Proteins; D025801:Ubiquitin; D057149:Ubiquitinated Proteins; C471607:UBE2N protein, human; D044763:Ubiquitin-Conjugating Enzymes; D000072017:Deubiquitinating Enzymes; C538826:OTUB1 protein, human; D003546:Cysteine Endopeptidases