Active site remodelling accompanies thioester bond formation in the SUMO E1

Journal Article · Tue Mar 30 04:00:00 EDT 2010 · Nature

DOI:https://doi.org/10.1038/nature08765· OSTI ID:1002312

Olsen, Shaun K; Capili, Allan D; Lu, Xuequan; Tan, Derek S; Lima, Christopher D ^[1]

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1. SKI

E1 enzymes activate ubiquitin (Ub) and ubiquitin-like (Ubl) proteins in two steps by carboxy-terminal adenylation and thioester bond formation to a conserved catalytic cysteine in the E1 Cys domain. The structural basis for these intermediates remains unknown. Here we report crystal structures for human SUMO E1 in complex with SUMO adenylate and tetrahedral intermediate analogues at 2.45 and 2.6 {angstrom}, respectively. These structures show that side chain contacts to ATP-Mg are released after adenylation to facilitate a 130 degree rotation of the Cys domain during thioester bond formation that is accompanied by remodelling of key structural elements including the helix that contains the E1 catalytic cysteine, the crossover and re-entry loops, and refolding of two helices that are required for adenylation. These changes displace side chains required for adenylation with side chains required for thioester bond formation. Mutational and biochemical analyses indicate these mechanisms are conserved in other E1s.

• Research Organization: Advanced Photon Source (APS), Argonne National Laboratory (ANL), Argonne, IL (US)
• Sponsoring Organization: USDOE
• OSTI ID: 1002312
• Journal Information: Nature, Journal Name: Nature Journal Issue: 02, 2010 Vol. 463
• Country of Publication: United States
• Language: ENGLISH

Related Subjects

36 MATERIALS SCIENCE
CHAINS
CRYSTAL STRUCTURE
CYSTEINE
ENZYMES
PROTEINS
REENTRY
ROTATION