2VRR: Structure of SUMO modified Ubc9

Citation:
Abstract
Posttranslational modification with small ubiquitin-related modifier, SUMO, is a widespread mechanism for rapid and reversible changes in protein function. Considering the large number of known targets, the number of enzymes involved in modification seems surprisingly low: a single E1, a single E2, and a few distinct E3 ligases. Here we show that autosumoylation of the mammalian E2-conjugating enzyme Ubc9 at Lys14 regulates target discrimination. While not altering its activity toward HDAC4, E2-25K, PML, or TDG, sumoylation of Ubc9 impairs its activity on RanGAP1 and strongly activates sumoylation of the transcriptional regulator Sp100. Enhancement depends on a SUMO-interacting motif (SIM) in Sp100 that creates an additional interface with the SUMO conjugated to the E2, a mechanism distinct from Ubc9 approximately SUMO thioester recruitment. The crystal structure of sumoylated Ubc9 demonstrates how the newly created binding interface can provide a gain in affinity otherwise provided by E3 ligases.
PDB ID: 2VRRDownload
MMDB ID: 66132
PDB Deposition Date: 2008/4/13
Updated in MMDB: 2012/11
Experimental Method:
x-ray diffraction
Resolution: 2.22  Å
Source Organism:
Mus musculus
Similar Structures:
Biological Unit for 2VRR: dimeric; determined by author and by software (PQS)
Molecular Components in 2VRR
Label Count Molecule
Proteins (2 molecules)
1
Sumo-conjugating Enzyme Ubc9(Gene symbol: Ube2i)
Molecule annotation
1
Small Ubiquitin-related Modifier 1(Gene symbol: SUMO1)
Molecule annotation
Chemicals (5 molecules)
1
4
2
1
* Click molecule labels to explore molecular sequence information.

Citing MMDB
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