5v1a

Structure of S. cerevisiae Ulp2:Csm1 complex

spinqualitylabelsall models 5v1a, resolution 2.14Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 5v1a is a 2 chain structure with sequence from Saccharomyces cerevisiae S288C. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Method: X-ray diffraction, Resolution 2.14Å Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function ULP2_YEAST Insertion mutation in SMT4 confers temperature and benomyl sensitivity; high copy suppressor of a temperature sensitive mutation in MIF2. Publication Abstract from PubMed Post-translational modification by SUMO (small ubiquitin-like modifier) plays important but still poorly understood regulatory roles in eukaryotic cells, including as a signal for ubiquitination by SUMO targeted ubiquitin ligases (STUbLs). Here, we delineate the molecular mechanisms for SUMO-dependent control of ribosomal DNA (rDNA) silencing through the opposing actions of a STUbL (Slx5:Slx8) and a SUMO isopeptidase (Ulp2). We identify a conserved region in the Ulp2 C terminus that mediates its specificity for rDNA-associated proteins and show that this region binds directly to the rDNA-associated protein Csm1. Two crystal structures show that Csm1 interacts with Ulp2 and one of its substrates, the rDNA silencing protein Tof2, through adjacent conserved interfaces in its C-terminal domain. Disrupting Csm1's interaction with either Ulp2 or Tof2 dramatically reduces rDNA silencing and causes a marked drop in Tof2 abundance, suggesting that Ulp2 promotes rDNA silencing by opposing STUbL-mediated degradation of silencing proteins. Tof2 abundance is rescued by deletion of the STUbL SLX5 or disruption of its SUMO-interacting motifs, confirming that Tof2 is targeted for degradation in a SUMO- and STUbL-dependent manner. Overall, our results demonstrate how the opposing actions of a localized SUMO isopeptidase and a STUbL regulate rDNA silencing by controlling the abundance of a key rDNA silencing protein, Tof2. Recruitment of a SUMO isopeptidase to rDNA stabilizes silencing complexes by opposing SUMO targeted ubiquitin ligase activity.,Liang J, Singh N, Carlson CR, Albuquerque CP, Corbett KD, Zhou H Genes Dev. 2017 Apr 15;31(8):802-815. doi: 10.1101/gad.296145.117. Epub 2017 May , 9. PMID:28487408 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

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