5n4w

<StructureSection load='5n4w' size='340' side='right' caption='[[5n4w]], [[Resolution|resolution]] 3.90&Aring;' scene=''>

<table><tr><td colspan='2'>[[5n4w]] is a 5 chain structure. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=5N4W OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=5N4W FirstGlance]. <br>

</td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat"><scene name='pdbligand=ZN:ZINC+ION'>ZN</scene></td></tr>

<tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=5n4w FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=5n4w OCA], [http://pdbe.org/5n4w PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=5n4w RCSB], [http://www.ebi.ac.uk/pdbsum/5n4w PDBsum], [http://prosat.h-its.org/prosat/prosatexe?pdbcode=5n4w ProSAT]</span></td></tr>

== Disease ==

[[http://www.uniprot.org/uniprot/VHL_HUMAN VHL_HUMAN]] Defects in VHL are a cause of susceptibility to pheochromocytoma (PCC) [MIM:[http://omim.org/entry/171300 171300]]. A catecholamine-producing tumor of chromaffin tissue of the adrenal medulla or sympathetic paraganglia. The cardinal symptom, reflecting the increased secretion of epinephrine and norepinephrine, is hypertension, which may be persistent or intermittent. Defects in VHL are the cause of von Hippel-Lindau disease (VHLD) [MIM:[http://omim.org/entry/193300 193300]]. VHLD is a dominantly inherited familial cancer syndrome characterized by the development of retinal angiomatosis, cerebellar and spinal hemangioblastoma, renal cell carcinoma (RCC), phaeochromocytoma and pancreatic tumors. VHL type 1 is without pheochromocytoma, type 2 is with pheochromocytoma. VHL type 2 is further subdivided into types 2A (pheochromocytoma, retinal angioma, and hemangioblastomas without renal cell carcinoma and pancreatic cyst) and 2B (pheochromocytoma, retinal angioma, and hemangioblastomas with renal cell carcinoma and pancreatic cyst). VHL type 2C refers to patients with isolated pheochromocytoma without hemangioblastoma or renal cell carcinoma. The estimated incidence is 3/100000 births per year and penetrance is 97% by age 60 years.<ref>PMID:10635329</ref> <ref>PMID:8493574</ref> <ref>PMID:7987306</ref> <ref>PMID:7728151</ref> <ref>PMID:8634692</ref> <ref>PMID:8592333</ref> <ref>PMID:8825918</ref> <ref>PMID:8730290</ref> <ref>PMID:8956040</ref> <ref>PMID:9452032</ref> <ref>PMID:9452106</ref> <ref>PMID:10627136</ref> <ref>PMID:9829911</ref> <ref>PMID:9829912</ref> [:]<ref>PMID:10533030</ref> <ref>PMID:10408776</ref> <ref>PMID:16502427</ref> Defects in VHL are the cause of familial erythrocytosis type 2 (ECYT2) [MIM:[http://omim.org/entry/263400 263400]]; also called VHL-dependent polycythemia or Chuvash type polycythemia. ECYT2 is an autosomal recessive disorder characterized by an increase in serum red blood cell mass, hypersensitivity of erythroid progenitors to erythropoietin, increased erythropoietin serum levels, and normal oxygen affinity. Patients with ECYT2 carry a high risk for peripheral thrombosis and cerebrovascular events.<ref>PMID:12844285</ref> <ref>PMID:12393546</ref> Defects in VHL are a cause of renal cell carcinoma (RCC) [MIM:[http://omim.org/entry/144700 144700]]. Renal cell carcinoma is a heterogeneous group of sporadic or hereditary carcinoma derived from cells of the proximal renal tubular epithelium. It is subclassified into clear cell renal carcinoma (non-papillary carcinoma), papillary renal cell carcinoma, chromophobe renal cell carcinoma, collecting duct carcinoma with medullary carcinoma of the kidney, and unclassified renal cell carcinoma.<ref>PMID:11986208</ref>

[[http://www.uniprot.org/uniprot/ELOB_HUMAN ELOB_HUMAN]] SIII, also known as elongin, is a general transcription elongation factor that increases the RNA polymerase II transcription elongation past template-encoded arresting sites. Subunit A is transcriptionally active and its transcription activity is strongly enhanced by binding to the dimeric complex of the SIII regulatory subunits B and C (elongin BC complex).<ref>PMID:7638163</ref> <ref>PMID:15590694</ref> The elongin BC complex seems to be involved as an adapter protein in the proteasomal degradation of target proteins via different E3 ubiquitin ligase complexes, including the von Hippel-Lindau ubiquitination complex CBC(VHL). By binding to BC-box motifs it seems to link target recruitment subunits, like VHL and members of the SOCS box family, to Cullin/RBX1 modules that activate E2 ubiquitination enzymes.<ref>PMID:7638163</ref> <ref>PMID:15590694</ref> [[http://www.uniprot.org/uniprot/CUL2_HUMAN CUL2_HUMAN]] Core component of multiple cullin-RING-based ECS (ElonginB/C-CUL2/5-SOCS-box protein) E3 ubiquitin-protein ligase complexes, which mediate the ubiquitination of target proteins. May serve as a rigid scaffold in the complex and may contribute to catalysis through positioning of the substrate and the ubiquitin-conjugating enzyme. The E3 ubiquitin-protein ligase activity of the complex is dependent on the neddylation of the cullin subunit and is inhibited by the association of the deneddylated cullin subunit with TIP120A/CAND1 (By similarity). The functional specificity of the ECS complex depends on the substrate recognition component. ECS(VHL) mediates the ubiquitination of hypoxia-inducible factor (HIF). [[http://www.uniprot.org/uniprot/RBX1_HUMAN RBX1_HUMAN]] E3 ubiquitin ligase component of multiple cullin-RING-based E3 ubiquitin-protein ligase complexes which mediate the ubiquitination and subsequent proteasomal degradation of target proteins, including proteins involved in cell cycle progression, signal transduction, transcription and transcription-coupled nucleotide excision repair. The functional specificity of the E3 ubiquitin-protein ligase complexes depends on the variable substrate recognition components. As a component of the CSA complex promotes the ubiquitination of ERCC6 resulting in proteasomal degradation. Through the RING-type zinc finger, seems to recruit the E2 ubiquitination enzyme, like CDC34, to the complex and brings it into close proximity to the substrate. Probably also stimulates CDC34 autoubiquitination. May be required for histone H3 and histone H4 ubiquitination in response to ultraviolet and for subsequent DNA repair. Promotes the neddylation of CUL1, CUL2, CUL4 and CUL4 via its interaction with UBE2M.<ref>PMID:10579999</ref> <ref>PMID:11027288</ref> <ref>PMID:16751180</ref> <ref>PMID:16678110</ref> <ref>PMID:19679664</ref> [[http://www.uniprot.org/uniprot/VHL_HUMAN VHL_HUMAN]] Involved in the ubiquitination and subsequent proteasomal degradation via the von Hippel-Lindau ubiquitination complex. Seems to act as target recruitment subunit in the E3 ubiquitin ligase complex and recruits hydroxylated hypoxia-inducible factor (HIF) under normoxic conditions. Involved in transcriptional repression through interaction with HIF1A, HIF1AN and histone deacetylases. Ubiquitinates, in an oxygen-responsive manner, ADRB2.<ref>PMID:9751722</ref> <ref>PMID:10944113</ref> <ref>PMID:19584355</ref> [[http://www.uniprot.org/uniprot/ELOC_HUMAN ELOC_HUMAN]] SIII, also known as elongin, is a general transcription elongation factor that increases the RNA polymerase II transcription elongation past template-encoded arresting sites. Subunit A is transcriptionally active and its transcription activity is strongly enhanced by binding to the dimeric complex of the SIII regulatory subunits B and C (elongin BC complex).<ref>PMID:15590694</ref> The elongin BC complex seems to be involved as an adapter protein in the proteasomal degradation of target proteins via different E3 ubiquitin ligase complexes, including the von Hippel-Lindau ubiquitination complex CBC(VHL). By binding to BC-box motifs it seems to link target recruitment subunits, like VHL and members of the SOCS box family, to Cullin/RBX1 modules that activate E2 ubiquitination enzymes.<ref>PMID:15590694</ref>

Cullin RING E3 ubiquitin ligases (CRLs) function in the ubiquitin proteasome system to catalyze the transfer of ubiquitin from E2 conjugating enzymes to specific substrate proteins. CRLs are large dynamic complexes and attractive drug targets for the development of small-molecule inhibitors and chemical inducers of protein degradation. The atomic details of whole CRL assembly and interactions that dictate subunit specificity remain elusive. Here we present the crystal structure of a pentameric CRL2VHL complex, composed of Cul2, Rbx1, Elongin B, Elongin C, and pVHL. The structure traps a closed state of full-length Cul2 and a new pose of Rbx1 in a trajectory from closed to open conformation. We characterize hotspots and binding thermodynamics at the interface between Cul2 and pVHL-EloBC and identify mutations that contribute toward a selectivity switch for Cul2 versus Cul5 recognition. Our findings provide structural and biophysical insights into the whole Cul2 complex that could aid future drug targeting.

 

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== References ==

[[Category: Cardote, T A.F]]

[[Category: Ciulli, A]]

[[Category: Gadd, M S]]

[[Category: Cullin ring]]

[[Category: Cullin-2]]

[[Category: Vhl]]