In cellulo crystallization of Trypanosoma brucei IMP dehydrogenase enables the identification of genuine co-factors

• Published in: Nature communications Vol. 11; no. 1; p. 620
• Main Authors: Nass, Karol, Redecke, Lars, Perbandt, M., Yefanov, O., Klinge, M., Koopmann, R., Stellato, F., Gabdulkhakov, A., Schönherr, R., Rehders, D., Lahey-Rudolph, J. M., Aquila, A., Barty, A., Basu, S., Doak, R. B., Duden, R., Frank, M., Fromme, R., Kassemeyer, S., Katona, G., Kirian, R., Liu, H., Majoul, I., Martin-Garcia, J. M., Messerschmidt, M., Shoeman, R. L., Weierstall, U., Westenhoff, S., White, T. A., Williams, G. J., Yoon, C. H., Zatsepin, N., Fromme, P., Duszenko, M., Chapman, H. N., Betzel, C.
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 30.01.2020; Nature Publishing Group; Nature Portfolio
• Subjects: 14/63; 5-monophosphate; 631/45; 631/535/1266; Adenosine triphosphate; African trypanosomiasis; Allosteric properties; Amino Acid Sequence; Animals; ATP; Binding Sites; Biochemistry; Biological Sciences; Biologiska vetenskaper; Biosynthesis; Catalytic activity; Catalytic Domain; Cloning, Molecular; Coenzymes - chemistry; Crystal growth; Crystal structure; Crystallization; crystallography; Crystals; Dehydrogenase; Dehydrogenases; Domains; Free electron lasers; Guanine; Guanosine; Guanosine Monophosphate; Humanities and Social Sciences; IMP dehydrogenase; IMP Dehydrogenase - chemistry; inhibitors; inosine 5'-monophosphate dehydrogenase; Insect cells; Insects; Laser radiation; MATERIALS SCIENCE; mechanism; Models, Molecular; monophosphate dehydrogenase; multidisciplinary; Nucleotides; Parasites; Protein Conformation; Protozoa; radiation-damage; reveals; Room temperature; Science; Science & Technology - Other Topics; Science (multidisciplinary); serial femtosecond; Sf9 Cells; Therapeutic targets; Trypanosoma brucei; Trypanosoma brucei brucei - enzymology; Trypanosoma brucei brucei - genetics; Vector-borne diseases; vivo protein crystallization; X-ray crystallography; X-rays
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/s41467-020-14484-w

Sleeping sickness is a fatal disease caused by the protozoan parasite Trypanosoma brucei (Tb). Inosine-5’-monophosphate dehydrogenase (IMPDH) has been proposed as a potential drug target, since it maintains the balance between guanylate deoxynucleotide and ribonucleotide levels that is pivotal for the parasite. Here we report the structure of TbIMPDH at room temperature utilizing free-electron laser radiation on crystals grown in living insect cells. The 2.80 Å resolution structure reveals the presence of ATP and GMP at the canonical sites of the Bateman domains, the latter in a so far unknown coordination mode. Consistent with previously reported IMPDH complexes harboring guanosine nucleotides at the second canonical site, TbIMPDH forms a compact oligomer structure, supporting a nucleotide-controlled conformational switch that allosterically modulates the catalytic activity. The oligomeric TbIMPDH structure we present here reveals the potential of in cellulo crystallization to identify genuine allosteric co-factors from a natural reservoir of specific compounds. Trypanosoma brucei inosine-5′-monophosphate dehydrogenase (IMPDH) is an enzyme in the guanine nucleotide biosynthesis pathway and of interest as a drug target. Here the authors present the 2.8 Å room temperature structure of TbIMPDH determined by utilizing X-ray free-electron laser radiation and crystals that were grown in insect cells and find that ATP and GMP are bound at the canonical sites of the Bateman domains.