title: Crystal structure of the tet repressor in complex with a novel tetracycline, 9-(N,N-dimethylglycylamido)- 6-demethyl-6-deoxy-tetracycline.
abstract: The tetracycline analog 9-(N, N-dimethylglycylamido)-6-demethyl-6-deoxy-tetracycline (9glyTc) belongs to a new group of tetracyclines called glycylcyclines. They are strong antibiotics showing reduced sensitivity against the major tetracycline resistance mechanisms. We have determined the crystal structure of 9glyTc in complex with Tet repressor class D, TetR(D), at 2.4 A resolution. Sterical hindrance at the entrance of the tetracycline binding tunnel of TetR by the bulky and charged glycyl amido substituent interferes with conformational changes required for the mechanism of induction, and leads to decreased induction efficiency as observed for point mutations of amino acid residues located in the neighbourhood to the glycylamido moiety of bound 9glyTc.
authors.affiliation: Freie Universität Berlin, Takustr. 6, Berlin, D-14195, Germany.
authors.forename: P
authors.initials: P
authors.lastname: Orth
authors.forename: D
authors.initials: D
authors.lastname: Schnappinger
authors.forename: P E
authors.initials: PE
authors.lastname: Sum
authors.forename: G A
authors.initials: GA
authors.lastname: Ellestad
authors.forename: W
authors.initials: W
authors.lastname: Hillen
authors.forename: W
authors.initials: W
authors.lastname: Saenger
authors.forename: W
authors.initials: W
authors.lastname: Hinrichs
mesh_terms: D018360:Crystallography, X-Ray; D046911:Macromolecular Substances; D015394:Molecular Structure; D016296:Mutagenesis; D011487:Protein Conformation; D012097:Repressor Proteins / Q000737:chemistry* / Q000378:metabolism; D013754:Tetracyclines / Q000737:chemistry* / Q000378:metabolism
chemical_list: D046911:Macromolecular Substances; D012097:Repressor Proteins; D013754:Tetracyclines; C034811:tetracycline resistance-encoding transposon repressor protein; C085306:6-demethyl-9-(N,N-dimethylglycylamido)-6-deoxytetracycline