TY - JOUR
T1 - A role for intersubunit interactions in maintaining SAGA deubiquitinating module structure and activity
AU - Samara, Nadine L.
AU - Ringel, Alison E.
AU - Wolberger, Cynthia
N1 - Funding Information:
We thank Mario Bianchet and Chris Berndsen for helpful comments and suggestions, Anthony DiBello for providing diubiquitin chains and wild-type DUB module, and Xiangbin Zhang for the purification of DUBm-S149N. This work was supported by NIH Grant R01GM095822. GM/CA-CAT has been funded by the National Cancer Institute (Y1-CO-1020) and the National Institute of General Medical Sciences (Y1-GM-1104). Use of the Advanced Photon Source was supported by the U.S. Department of Energy, Basic Energy Sciences, Office of Science, under contract No. DE-AC02-06CH11357.
PY - 2012/8/8
Y1 - 2012/8/8
N2 - The deubiquitinating module (DUBm) of the SAGA coactivator contains the Ubp8 isopeptidase, Sgf11, Sus1, and Sgf73, which form a highly interconnected complex. Although Ubp8 contains a canonical USP catalytic domain, it is only active when in complex with the other DUBm subunits. The Sgf11 zinc finger (Sgf11-ZnF) binds near the Ubp8 active site and is essential for full activity, suggesting that the Sgf11-ZnF helps maintain the active conformation of Ubp8. We report structural and solution studies showing that deletion of the Sgf11-ZnF destabilizes incorporation of Ubp8 within the DUBm, giving rise to domain swapping with a second complex and misaligning active site residues. Activating mutations in Ubp8 that partially restore activity in the absence of the Sgf11-ZnF promote the monomeric form of the DUBm. Our data suggest an unexpected role for Sgf11 in compensating for the absence of structural features that maintain the active conformation of Ubp8.
AB - The deubiquitinating module (DUBm) of the SAGA coactivator contains the Ubp8 isopeptidase, Sgf11, Sus1, and Sgf73, which form a highly interconnected complex. Although Ubp8 contains a canonical USP catalytic domain, it is only active when in complex with the other DUBm subunits. The Sgf11 zinc finger (Sgf11-ZnF) binds near the Ubp8 active site and is essential for full activity, suggesting that the Sgf11-ZnF helps maintain the active conformation of Ubp8. We report structural and solution studies showing that deletion of the Sgf11-ZnF destabilizes incorporation of Ubp8 within the DUBm, giving rise to domain swapping with a second complex and misaligning active site residues. Activating mutations in Ubp8 that partially restore activity in the absence of the Sgf11-ZnF promote the monomeric form of the DUBm. Our data suggest an unexpected role for Sgf11 in compensating for the absence of structural features that maintain the active conformation of Ubp8.
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U2 - 10.1016/j.str.2012.05.015
DO - 10.1016/j.str.2012.05.015
M3 - Article
C2 - 22771212
AN - SCOPUS:84864848052
SN - 0969-2126
VL - 20
SP - 1414
EP - 1424
JO - Structure
JF - Structure
IS - 8
ER -