title: The conformations of trimethoprim/E. coli dihydrofolate reductase complexes. A 15N and 31P NMR study.
abstract: We have employed 15N and 31P NMR techniques to characterize the conformations of trimethoprim (TMP)/E. coli dihydrofolate reductase (DHFR) complexes in the presence and absence of NADPH and NADP+. A single conformation was observed for TMP/DHFR, NADP+/DHFR, NADPH/DHFR, and TMP/NADPH/DHFR complexes. In the ternary complex of TMP/NADP+/DHFR both the 15N and 31P spectra revealed the presence of two conformations. However, the conformations of TMP and NADP+ in the ternary complex may not be correlated, resulting in the possible existence of four conformations for the protein ternary complex.
authors.affiliation: School of Physics, Georgia Institute of Technology, Atlanta 30332.
authors.forename: F Y
authors.initials: FY
authors.lastname: Huang
authors.forename: Q X
authors.initials: QX
authors.lastname: Yang
authors.forename: T H
authors.initials: TH
authors.lastname: Huang
authors.forename: L
authors.initials: L
authors.lastname: Gelbaum
authors.forename: L F
authors.initials: LF
authors.lastname: Kuyper
mesh_terms: D004926:Escherichia coli / Q000201:enzymology*; D006863:Hydrogen-Ion Concentration; D009682:Magnetic Resonance Spectroscopy; D009249:NADP / Q000737:chemistry; D009587:Nitrogen Isotopes; D010759:Phosphorus Isotopes; D011487:Protein Conformation; D013762:Tetrahydrofolate Dehydrogenase / Q000737:chemistry*; D014295:Trimethoprim / Q000737:chemistry*
chemical_list: D009587:Nitrogen Isotopes; D010759:Phosphorus Isotopes; D009249:NADP; D014295:Trimethoprim; D013762:Tetrahydrofolate Dehydrogenase