6fmk
pVHL:EloB:EloC in complex with N-((S)-1-((2S,4R)-4-hydroxy-2-((4-(4-methylthiazol-5-yl)benzyl)carbamothioyl) pyrrolidin-1-yl)-1-thioxopropan-2-yl)acetamide (ligand 4)pVHL:EloB:EloC in complex with N-((S)-1-((2S,4R)-4-hydroxy-2-((4-(4-methylthiazol-5-yl)benzyl)carbamothioyl) pyrrolidin-1-yl)-1-thioxopropan-2-yl)acetamide (ligand 4)
Structural highlights
FunctionELOB_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).[1] [2] 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.[3] [4] Publication Abstract from PubMedThioamide substitution influences hydrogen bond and n --> pi( *) interactions involved in the conformational stability of protein secondary structures and oligopeptides. Hydroxyproline is the key recognition element of small molecules targeting the von Hippel-Lindau (VHL) E3 ligase, which are of interest as probes of hypoxia signaling and ligands for PROTAC conjugation. We hypothesized that VHL ligands could be a privileged model system to evaluate the contribution of these interactions to protein:ligand complex formation. Herein we report the synthesis of VHL ligands bearing thioamide substitutions at the central hydroxyproline moiety, and characterize their binding by fluorescence polarization, isothermal titration calorimetry, X-ray crystallography and molecular modeling. In spite of a conserved binding mode, the substitution pattern had a pronounced impact on the ligand affinities. Together the results underscore the role of hydrogen bond and n --> pi( *) interactions in fine tuning hydroxyproline recognition by VHL. Thioamide substitution to probe the hydroxyproline recognition of VHL ligands.,Soares P, Lucas X, Ciulli A Bioorg Med Chem. 2018 Mar 23. pii: S0968-0896(18)30348-1. doi:, 10.1016/j.bmc.2018.03.034. PMID:29650462[5] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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