title: Aminoglycoside antibiotics bound to aminoglycoside-detoxifying enzymes and RNA adopt similar conformations.
abstract: Conformations of ribostamycin and isepamicin, aminoglycoside antibiotics, bound to an aminoglycoside antibiotic, 3'-phosphotransferase, were determined by transferred nuclear Overhauser effect spectroscopy and molecular modeling. Two major conformers of enzyme-bound ribostamycin, a neomycin-group aminoglyeoside were observed. The 3'- and 5"-OH groups (reactive hydroxyl groups) in the conformers are placed in approximate locations. One of the conformers is similar to the structure of paromomycin bound to a 27-nucleotide piece of ribosomal RNA that represents the A-site of the small ribosomal subunit, where rings A and C are in an orthogonal arrangement. Isepamicin, a kanamycin-group aminoglycoside antibiotic, also showed two major enzyme-bound conformations. Both conformations were similar to those observed for bound isepamicin in the active site of an aminoglycoside(6')-acetyl transferase-Ii. Conformations of other RNA-bound kanamycin-group aminoglycosides were also similar to the enzyme-bound conformations of isepamicin. These observations suggest that aminoglycosides may adopt similar conformations when bound to RNA and protein targets. This may have significant implications in the design of enzyme inhibitors and/or antibiotics.
authors.affiliation: Murray State University, KY 4207-3346, USA.
authors.forename: J R
authors.initials: JR
authors.lastname: Cox
authors.forename: D R
authors.initials: DR
authors.lastname: Ekman
authors.forename: E L
authors.initials: EL
authors.lastname: DiGiammarino
authors.forename: A
authors.initials: A
authors.lastname: Akal-Strader
authors.forename: E H
authors.initials: EH
authors.lastname: Serpersu
mesh_terms: D000818:Animals; D007612:Kanamycin / Q000737:chemistry* / Q000378:metabolism; D019868:Kanamycin Kinase / Q000737:chemistry* / Q000378:metabolism; D009690:Nucleic Acid Conformation; D011485:Protein Binding; D011487:Protein Conformation; D012335:RNA, Ribosomal / Q000737:chemistry* / Q000378:metabolism; D012271:Ribostamycin / Q000737:chemistry* / Q000378:metabolism; D013379:Substrate Specificity
chemical_list: D012335:RNA, Ribosomal; D012271:Ribostamycin; D007612:Kanamycin; D019868:Kanamycin Kinase