Preliminary joint X-ray and neutron protein crystallographic studies of ecDHFR complexed with folate and NADP⁺

Authors

• Qun Wan, Yangzhou UniversityFollow
• Audrey Y. Kovalevsky, Oak Ridge National Laboratory
• Mark A. Wilson, University of Nebraska-LincolnFollow
• Brad C. Bennett, University of Virginia
• Paul Langan, Oak Ridge National Laboratory
• Chris Dealwis, Case Western Reserve UniversityFollow

Document Type

Article

Date of this Version

2014

Citation

Acta Cryst. (2014). F70, 814–818

doi:10.1107/S2053230X1400942X

Comments

Copyright 2014 International Union of Crystallography All rights reserved

Abstract

A crystal of Escherichia coli dihydrofolate reductase (ecDHFR) complexed with folate and NADP⁺ of 4 x 1.3 x 0.7 mm (3.6 mm³) in size was obtained by sequential application of microseeding and macroseeding. A neutron diffraction data set was collected to 2.0 A resolution using the IMAGINE diffractometer at the High Flux Isotope Reactor within Oak Ridge National Laboratory. A 1.6 A resolution X-ray data set was also collected from a smaller crystal at room temperature. The neutron and X-ray data were used together for joint refinement of the ecDHFR–folate–NADP⁺ ternary-complex structure in order to examine the protonation state, protein dynamics and solvent structure of the complex, furthering understanding of the catalytic mechanism.