The conformations of trimethoprim/E. coli dihydrofolate reductase complexes. A 15N and 31P NMR study.
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.
Huang
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School of Physics, Georgia Institute of Technology, Atlanta 30332.
Yang
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Huang
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Gelbaum
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Kuyper
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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*
D009587:Nitrogen Isotopes; D010759:Phosphorus Isotopes; D009249:NADP; D014295:Trimethoprim; D013762:Tetrahydrofolate Dehydrogenase