- PhD, California Institute of Technology, 1974
- BS, Michigan State University, 1970
- Electron transport proteins
- NMR analysis of 3D protein structure
- Biosynthesis of novel tetrapyrroles
Research comprises two main areas: the structure and mechanism of operation of electron transport proteins; the structure and biosynthesis of unusual tetrapyrroles. High resolution NMR techniques in combination with molecular dynamics and energy minimization are being applied to determine structure for cytochromes and other electron transport proteins. The wallpaper on this page is a small portion of a two-dimensional COSY spectrum of cyt c-551 showing the spin-coupling interactions between aromatic protons. In the second main area, chemical spectroscopy (NMR, mass spectrometry, UV-visible spectroscopy, FT-IR) is applied to determine the structure of unusual porphyrins that are found as the active site prosthetic group in some enzymes. The biosynthetic pathway of these molecules is being explored by the use of stable isotope enrichment of presumed precursors, and by the isolation and characterization of natural metabolic precursors.
“The metal binding site of zoocin A.” Chen, Y.; Simmonds, R. S.; Sloan, G. L.; Timkovich, R. JBIC, J. Biol. Inorg. Chem. 13, 855-860 (2008).
“Heme crevice disorder after sixth ligand displacement in the cytochrome c-551 family.” Chen, Y.; Liang, Q.; Arciero, D. M.; Hooper, A. B.; Timkovich, R. Arch. Biochem. Biophys. 457, 95-104 (2007).
“Solution conformation of the His-47 to Ala-47 mutant of Pseudomonas stutzeri ZoBell ferrocytochrome c-551.” Liang, Q.; Miller, G. T.; Beeghley, C. A.; Graf, C. B.; Timkovich, R. Biophys. J. 93, 1700-1706 (2007).
“Siro(haem)amide in Allochromatium vinosum and relevance of DsrL and DsrN, a homolog of cobyrinic acid a,c-diamide synthase, for sulphur oxidation.” Luebbe, Y. J.; Youn, H.-S.; Timkovich, R.; Dahl, C. FEMS Microbiology Letters 261, 194-202 (2006).
“Mutation of the Putative Hydrogen-Bond Donor to P700 of Photosystem I.” Li, Y.; Lucas, M.-G.; Konovalova, T.; Abbott, B.; MacMillan, F.; Petrenko, A.; Sivakumar, V.; Wang, R.; Hastings, G.; Gu, F.; van Tol, J.; Brunel, L.-C.; Timkovich, R.; Rappaport, F.; Redding, K., Biochemistry, 43, 12634-12647 (2004).
“Compound 800, a natural product isolated from genetically engineered Pseudomonas: Proposed structure, reactivity, and putative relation to heme d1.” Youn, H.-S.; Liang, Q.; Cha, J. K.; Cai, M.; Timkovich, R., Biochemistry, 43, 10730-10738 (2004).
“NMR evidence for independent domain structures in zoocin A, an antibacterial exoenzyme.” Liang, Q.; Simmonds, R. S.; Timkovich, R., Biochem. Biophys. Res. Commun., 317, 527-530 (2004).
“Identification of hemes and related cyclic tetrapyrroles by matrix-assisted laser desorption/ionization and liquid secondary ion mass spectrometry.” Youn, H.-S.; Burkhalter, R. S.; Timkovich, R., Rapid Comm. Mass Spect., 16, 1147-1152 (2002).
“Solution Conformation of the Met 61 to His 61 mutant of Pseudomonas stutzeri ZoBell Ferrocytochrome c-551,” G. T. Miller, J. K. Hardman, and R. Timkovich Biophys. J. 80, 2928-2934 (2001).
“A Complex of Iron and Nucleic Acid Catabolites is a Signal that Triggers Differentiation in a Freshwater Protozoan,” H.E. Smith-Somerville, J.K. Hardman, R. Timkovich, W.J. Ray, K.E. Rose, P.E. Ryals, S.H. Gibbons, and H.E. Buhse, Jr., Proc. Nat. Acad. Sci., 97, 7325-7330 (2000).