title: Structural Basis of Telomerase Inhibition by the Highly Specific BIBR1532.
abstract: BIBR1532 is a highly specific telomerase inhibitor, although the molecular basis for inhibition is unknown. Here we present the crystal structure of BIBR1532 bound to Tribolium castaneum catalytic subunit of telomerase (tcTERT). BIBR1532 binds to a conserved hydrophobic pocket (FVYL motif) on the outer surface of the thumb domain. The FVYL motif is near TRBD residues that bind the activation domain (CR4/5) of hTER. RNA binding assays show that the human TERT (hTERT) thumb domain binds the P6.1 stem loop of CR4/5 in vitro. hTERT mutations of the FVYL pocket alter wild-type CR4/5 binding and cause telomere attrition in cells. Furthermore, the hTERT FVYL mutations V1025F, N1028H, and V1090M are implicated in dyskeratosis congenita and aplastic anemia, further supporting the biological and clinical relevance of this novel motif. We propose that CR4/5 contacts with the telomerase thumb domain contribute to telomerase ribonucleoprotein assembly and promote enzymatic activity.
authors.affiliation: The Wistar Institute, 3601 Spruce Street, Philadelphia, PA 19104, USA; Department of Chemistry, University of Pennsylvania, 231 South 34th Street, Philadelphia, PA 19104, USA.
authors.forename: Christopher
authors.initials: C
authors.lastname: Bryan
authors.affiliation: The Wistar Institute, 3601 Spruce Street, Philadelphia, PA 19104, USA; Department of Biochemistry, University of Pennsylvania, Philadelphia, PA 19104, USA.
authors.forename: Cory
authors.initials: C
authors.lastname: Rice
authors.affiliation: The Wistar Institute, 3601 Spruce Street, Philadelphia, PA 19104, USA.
authors.forename: Hunter
authors.initials: H
authors.lastname: Hoffman
authors.affiliation: The Wistar Institute, 3601 Spruce Street, Philadelphia, PA 19104, USA.
authors.forename: Michael
authors.initials: M
authors.lastname: Harkisheimer
authors.affiliation: The Wistar Institute, 3601 Spruce Street, Philadelphia, PA 19104, USA; Department of Chemistry, University of Pennsylvania, 231 South 34th Street, Philadelphia, PA 19104, USA.
authors.forename: Melanie
authors.initials: M
authors.lastname: Sweeney
authors.affiliation: The Wistar Institute, 3601 Spruce Street, Philadelphia, PA 19104, USA; Department of Chemistry, University of Pennsylvania, 231 South 34th Street, Philadelphia, PA 19104, USA; Department of Biochemistry, University of Pennsylvania, Philadelphia, PA 19104, USA. Electronic address: skorda@wistar.org.
authors.forename: Emmanuel
authors.initials: E
authors.lastname: Skordalakes
mesh_terms: D020816:Amino Acid Motifs; D062365:Aminobenzoates / Q000737:chemistry* / Q000494:pharmacology; D000818:Animals; D000970:Antineoplastic Agents / Q000737:chemistry* / Q000494:pharmacology; D001665:Binding Sites; D020134:Catalytic Domain / Q000235:genetics; D002460:Cell Line; D018360:Crystallography, X-Ray; D004791:Enzyme Inhibitors / Q000737:chemistry / Q000494:pharmacology; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism; D005347:Fibroblasts / Q000166:cytology / Q000187:drug effects / Q000201:enzymology; D015870:Gene Expression; D006801:Humans; D019476:Insect Proteins / Q000037:antagonists & inhibitors* / Q000235:genetics / Q000378:metabolism; D007700:Kinetics; D008958:Models, Molecular; D008969:Molecular Sequence Data; D009154:Mutation; D009281:Naphthalenes / Q000737:chemistry* / Q000494:pharmacology; D011485:Protein Binding; D054730:Protein Interaction Domains and Motifs; D017433:Protein Structure, Secondary; D012313:RNA / Q000737:chemistry* / Q000378:metabolism; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D019098:Telomerase / Q000037:antagonists & inhibitors* / Q000235:genetics / Q000378:metabolism; D014231:Tribolium
chemical_list: D062365:Aminobenzoates; D000970:Antineoplastic Agents; C458523:BIBR 1532; D004791:Enzyme Inhibitors; D019476:Insect Proteins; D009281:Naphthalenes; D011994:Recombinant Proteins; D012313:RNA; C509186:TERT protein, human; D019098:Telomerase