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Structural Basis for E2-mediated SUMO conjugation revealed by a complex between ubiquitin conjugating enzyme Ubc9 and RanGAP1
[UBC9_HUMAN] Accepts the ubiquitin-like proteins SUMO1, SUMO2, SUMO3 and SUMO4 from the UBLE1A-UBLE1B E1 complex and catalyzes their covalent attachment to other proteins with the help of an E3 ligase such as RANBP2 or CBX4. Can catalyze the formation of poly-SUMO chains. Necessary for sumoylation of FOXL2 and KAT5. Essential for nuclear architecture and chromosome segregation.      
Publication Abstract from PubMed
E2 enzymes catalyze attachment of ubiquitin and ubiquitin-like proteins to lysine residues directly or through E3-mediated reactions. The small ubiquitin-like modifier SUMO regulates nuclear transport, stress response, and signal transduction in eukaryotes and is essential for cell-cycle progression in yeast. In contrast to most ubiquitin conjugation, the SUMO E2 enzyme Ubc9 is sufficient for substrate recognition and lysine modification of known SUMO targets. Crystallographic analysis of a complex between mammalian Ubc9 and a C-terminal domain of RanGAP1 at 2.5 A reveals structural determinants for recognition of consensus SUMO modification sequences found within SUMO-conjugated proteins. Structure-based mutagenesis and biochemical analysis of Ubc9 and RanGAP1 reveal distinct motifs required for substrate binding and SUMO modification of p53, IkappaBalpha, and RanGAP1.
Structural basis for E2-mediated SUMO conjugation revealed by a complex between ubiquitin-conjugating enzyme Ubc9 and RanGAP1.,Bernier-Villamor V, Sampson DA, Matunis MJ, Lima CD Cell. 2002 Feb 8;108(3):345-56. PMID:11853669
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.