XRD Facility



X-ray Diffraction (XRD) Facility

A research facility for investigation of single crystal and powder/thin film samples by X-Ray diffraction techniques.






Training, experimental design and/or sample service.

Chemical Sciences Building

Visit Us!


Chemical Sciences Bldg. (CSB), Room 117


Monday thru Friday

8:00 AM to 5:00 PM

24/7 Access for Trained Users



The XRD Facility serves the Faculty of the UA Department of Chemistry and outside customers, both academic and non-academic. We can use X-ray crystallography to determine the structure of small molecules by studying the XRD from single crystal samples. We can also study the powder and thin film samples to determine the crystallinity, composition, and various other properties of such samples (e.g., the thickness of thin films, preferred orientation of crystallites, etc.). The instrumentation available includes the single crystal X-ray diffractometer (Bruker Kappa Apex II Duo) and the powder diffractometer (Philips / Panalytical X’Pert Pro MPD). Contact the facility manager for details.



The facility performs, twice a year, lab demonstrations for students of Chem 412 class. The students willing to learn the use of the single crystal and/or powder XRD instruments are welcome. Such students should contact the manager to arrange for training.

Facility Publications

Use the Keck RRID!

University of Arizona - UA CBC X-Ray Diffraction (XRD) Facility, RRID:SCR_022886


Little EJ, Dunten PW, Bitinaite J, Horton NC. New clues in the allosteric activation of DNA cleavage by SgrAI: structures of SgrAI bound to cleaved primary-site DNA and uncleaved secondary-site DNA. Acta Crystallogr D: Biol. Crystallogr. 2011; 67, 67-74.


Park CK, Joshi HK, Agrawal A, Ghare MI, Little EJ, Dunten PW, Bitinaite J, Horton NC. Domain swapping in allosteric modulation of DNA specificity PLOS Biol. 2010; 8, e1000554.

Horton NC, Park CK. Crystallization of zinc finger proteins bound to DNA. Methods Mol Biol. 2010; 649:457-77.

Weichsel A, Kem M, Montfort WR. Crystal structure of human thioredoxin revealing an unraveled helix and exposed S-nitrosation site.Protein Sci. 201019 1801-1806.


Robert E. Berry, Maxim N. Shokhirev, Arthur Y. W. Ho, Fei Yang, Tatiana K. Shokhireva, Hongjun Zhang, Andrzej Weichsel, William R. Montfort and F. Ann Walker. Effect of Mutation of Carboxyl Side-Chain Amino Acids Near the Heme on the Midpoint Potentials and Ligand Binding Constants of Nitrophorin 2 and Its NO, Histamine, and Imidazole Complexes J. Am. Chem. Soc., (2009)131, 2313–2327.

Dunten PW, Little EJ, Horton NC.The restriction enzyme SgrAI: structure solution via combination of poor MIRAS and MR phases. Acta Crystallogr D Biol Crystallogr. (2009) 65,393-8.

Campbell ZT, Weichsel A, Montfort WR, Baldwin TO. Crystal Structure of the Bacterial Luciferase/Flavin Complex Provides Insight into the Function of the β Subunit. Biochemistry, (2009)48, 6085–6094.

Loftin IR, Blackburn NJ, McEvoy MM. Tryptophan Cu(I)-pi interaction fine-tunes the metal binding properties of the bacterial metallochaperone CusF. J Biol Inorg Chem. 200914, 905-12.

Dexheimer TS, Carey SS, Zuohe S, Gokhale VM, Hu X, Murata LB, Maes EM, Weichsel A, Sun D, Meuillet EJ, Montfort, WR, Hurley LH. NM23-H2 may play an indirect role in transcriptional activation of c-myc gene expression but does not cleave the nuclease hypersensitive element III1. Mol Cancer Ther (2009)8, 1363-1377.


Matthew S. Dubrava, Wendy M. Ingram, Sue A. Roberts, Andrzej Weichsel, William R. Montfort, and Matthew H. J. Cordes .   N15 Cro and λ Cro: orthologous DNA-binding domains with completely different but equally effective homodimer interfaces, Protein Science (2008), 17 , 803-812.

Shane D. Morrison, Sue A. Roberts, Abreeza M. Zegeer, William R. Montfort, and Vahe Bandarian. A new use for a familiar fold: The x-ray crystal structure of GTP-bound GTP cyclohydrolase III from Methanocaldococcus jannaschii reveals a two metal ion catalytic mechanism.   Biochemistry (2008)47, 230-242.

Hall, Branwen M., Roberts, Sue A., Heroux, Annie M., Cordes, Matthew H. Two structures of a  λ-Cro variant highlight dimer flexibility but disfavor major dimer distortions upon specific binding of cognate DNA. J. Mol Biol (2008)375, 802-811.

Christian G. Roessler, Branwen M. Hall, William J. Anderson, Wendy M. Ingram, Sue A. Roberts, William R. Montfort, and Matthew H. J. Cordes.   Transitive homology-guided structural studies lead to discovery of Cro proteins with 40% sequence identity but different folds. PNAS (2008)105, 2343-2348.

Pete W. Dunten, Elizabeth J. Little, Mark T. Gregory, Veena M. Manohar, Michael Dalton, David Hough, Jurate Bitinaite, and Nancy C. Horton. The structure of SgrAI bound to DNA; recognition of an 8 base pair target. Nucl. Acids Res. (2008)36, 5405-5416.

Babic AC, Little EJ, Manohar VM, Bitinaite J, Horton NC. DNA distortion and specificity in a sequence-specific endonuclease. J Mol Biol. (2008), 383, 186-204.

James E. Spoonamore, Sue A. Roberts, Annie Heroux and Vahe Bandarian.   X-ray crystal structure of a 6-pyruvoyltetrahydropterin synthase homolog from Streptomyces coelicolor Acta Crystallogr. F. (2008), F64, 875-879.

Arvizu-Flores AA, Sugich-Miranda R, Arreola R, Garcia-Orozco KD, Velazquez-Contreras EF, Montfort WR, Maley F, Sotelo-Mundo RR. Role of an invariant lysine residue in folate binding on Escherichia coli thymidylate synthase: calorimetric and crystallographic analysis of the K48Q mutant. Int J Biochem Cell Biol. (2008)40 2206-17.

Little EJ, Babic AC, Horton NC. Early interrogation and recognition of DNA sequence by indirect readout. Structure. (2008)16, 1828-37.


Shokhireva TKh, Weichsel A, Smith KM, Berry RE, Shokhirev NV, Balfour CA, Zhang H, Montfort WR, Walker FA. Assignment of the Ferriheme Resonances of the Low-Spin Complexes of Nitrophorins 1 and 4 by 1H and 13C NMR Spectroscopy: Comparison to Structural Data Obtained from X-ray Crystallography. Inorganic Chemistry, (2007)46, 2041-2056.

Isabell R. Loftin, Sylvia Franke, Ninian J. Blackburn, and Megan M. McEvoy. Unusual Cu(I)/Ag(I) coordination of Escherichia coli CusF as revealed by atomic resolution crystallography and X-ray absorption spectroscopy Protein Sci, (2007)16, 2287-2293.

Schreiter ER, Rodríguez MM, Weichsel A, Montfort WR, Bonaventura J. S-nitrosylation-induced conformational change in blackfin tuna myoglobin. J. Biol. Chem., (2007), 282, 19773-80.

Weichsel, A., Brailey, JL, Montfort, WR. Buried S-Nitrosocysteine Revealed in Crystal Structures of Human Thioredoxin. Biochemistry, (2007)46, 1219-1227.


Roberts SA, Hyatt, DC, Honts, JE, Changchien C, Maley, GF, Maley F, Montfort WR. Y94F Mutant of E. coli Thymidylate S ynthase. Acta Crystallogr F62 (2006), 840-843.

Segal DJ, Crotty JW, Bhakta MS, Barbas CF, Horton NC. Structure of Aart, a designed six-finger zinc finger peptide, bound to DNA. J Mol Biol. (2006)363, 405-21.

Joshi HK, Etzkorn C, Chatwell L, Bitinaite J, Horton NC. Alteration of sequence specificity of the type II restriction endonuclease HincII through an indirect readout mechanism. J Biol Chem. (2006) 281,23852-69.

Weichsel A, Maes EM, Andersen JF, Valenzuela JG, Shokhireva, TK, Walker FA, and Montfort WR. Heme-assisted S-nitrosation of a proximal thiolate in a nitric oxide transport protein. Proc. Natl. Acad. Sci. USA, (2005)102, 594-599.

Maes EM, Roberts SA, Weichsel A, Montfort WR. Heme Distortion in Nitrophorin 4: Ultra-High Resolution Structures of Ferrous Complexes. Biochemistry, (2005)44,12690-12699.

Loftin IR, Franke S, Roberts SA, Weichsel A, Heroux A, Montfort WR, Rensing C, McEvoy M. A Novel Copper-binding Fold for the Periplasmic Metallochaperone Cusf. Biochemistry, (2005)44, 10533-10540.

Berry RE, Ding XD, Shokhireva TK, Weichsel A, Montfort WR, Walker FA. Axial ligand complexes of the Rhodnius nitrophorins: reduction potentials, binding constants, EPR spectra, and structures of the 4-iodopyrazole and imidazole complexes of NP4. J Biol Inorg Chem. (2004)9, 135-144.

Maes EM, Weichsel A, Andersen JF, Shepley D, Montfort WR. Role of Binding Site Loops in Controlling Nitric Oxide Release: Structure and Kinetics of Mutant Forms of Nitrophorin 4. Biochemistry (2004)43, 6679-6690.

Kondrashov DA, Roberts SA, Weichsel A, Montfort WR. Protein functional cycle viewed at atomic resolution: conformational change and mobility in nitrophorin 4 as a function of pH and NO binding. Biochemistry (2004)43, 13637-13647.

K. Nienhaus, E. M. Maes, A. Weichsel, W. R. Montfort and G. U. Nienhaus, Structural dynamics controls nitric oxide affinity in Nitrophorin 4 Journal of Biological Chemistry, (2004) 279, 39401-39407.

Roberts, Sue A.; Wildner, Guenter F.; Grass, Gregor; Weichsel, Andrzej; Ambrus, Attila; Rensing, Christopher; Montfort, William R. A Labile Regulatory Copper Ion Lies Near the T1 Copper Site in the Multicopper Oxidase CueO. J.Biol.Chem. (2003)278, 31958-31963.

Roberts, Sue A.; Weichsel, Andrzej; Grass, Gregor; Thakali, Keshari; Hazzard, James T.; Tollin, Gordon; Rensing, Christopher; Montfort, William R. Crystal structure and electron transfer kinetics of CueO, a multicopper oxidase required for copper homeostasis in Escherichia coli. PNAS (2002)99, 2766-2771.

Roberts, Sue A.; Weichsel, Andrzej; Qiu, Yan; Shelnutt, John A.; Walker, F. Ann; Montfort, William R. Ligand-Induced Heme Ruffling and Bent NO Geometry in Ultra-High-Resolution Structures of Nitrophorin 4. Biochemistry (2001)40, 11327-11337.

Weichsel, Andrzej; Andersen, John F.; Roberts, Sue A.; Montfort, William R. Nitric oxide binding to nitrophorin 4 induces complete distal pocket burial. Nature Struct Biol. (2000)7, 551-554.

Contact Us:

Andrei Astachkine, Ph.D.

Assistant Staff Scientist