Basis for a ubiquitin-like protein thioester switch toggling E1–E2 affinity

Huang, D. T. , Hunt, H. W., Zhuang, M., Ohi, M. D., Holton, J. M. and Schulman, B. A. (2007) Basis for a ubiquitin-like protein thioester switch toggling E1–E2 affinity. Nature, 445(7126), pp. 394-398. (doi: 10.1038/nature05490)

Abstract

Ubiquitin-like proteins (UBLs) are conjugated by dynamic E1–E2–E3 enzyme cascades. E1 enzymes activate UBLs by catalysing UBL carboxy-terminal adenylation, forming a covalent E1~UBL thioester intermediate, and generating a thioester-linked E2~UBL product, which must be released for subsequent reactions. Here we report the structural analysis of a trapped UBL activation complex for the human NEDD8 pathway, containing NEDD8's heterodimeric E1 (APPBP1–UBA3), two NEDD8s (one thioester-linked to E1, one noncovalently associated for adenylation), a catalytically inactive E2 (Ubc12), and MgATP. The results suggest that a thioester switch toggles E1–E2 affinities. Two E2 binding sites depend on NEDD8 being thioester-linked to E1. One is unmasked by a striking E1 conformational change. The other comes directly from the thioester-bound NEDD8. After NEDD8 transfer to E2, reversion to an alternate E1 conformation would facilitate release of the E2~NEDD8 thioester product. Thus, transferring the UBL's thioester linkage between successive conjugation enzymes can induce conformational changes and alter interaction networks to drive consecutive steps in UBL cascades.

• Item Type: Articles
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Huang, Professor Danny
• Authors: Huang, D. T., Hunt, H. W., Zhuang, M., Ohi, M. D., Holton, J. M., and Schulman, B. A.
• College/School: College of Medical Veterinary and Life Sciences > School of Cancer Sciences
• Journal Name: Nature
• ISSN: 0028-0836
• Published Online: 25 January 2007