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.