Dr. Christopher Steward Francklyn
Structure and Function of Nucleic Acid Binding Proteins
General Description: My lab focuses on the relationship of protein structure to function, particularly in the context of protein nucleic acid interactions. To better understand how genes are regulated, both at the transcriptional and translational level, we are studying the structural and functional basis of protein-DNA and protein-RNA recognition using diverse experimental tools including enzymology, molecular biology, fluorescence, and x-ray crystallography. We hope to discover systematic principles of protein-nucleic acid recognition by these approaches, and then apply these to the design of proteins with novel therapeutic or biotechnological applications. Our work focuses on three main project areas:
Structure and Function of Aminoacyl-tRNA Synthetases
Dock-Bregeon, A.-C., Sankaranarayan R., Romby, P., Caillet, J., Springer, M., Rees, B., Francklyn, C. S., Ehresmann, C., Moras, D. (2000) Transfer RNA mediated editing in the Class II Threonyl-tRNA Synthetase: The Class II Solution to the Double Discrimination Problem. Cell 103: 877-884.
Guth, E., Connolly, S.A, Bovee, M., & Francklyn, C.S. (2005) A substrate assisted concerted mechanism for aminoacylation of tRNAHis by histidyl-tRNA synthetase from Escherichia coli. Biochemistry. 44(10): 3785-3795.
Guth, E. & Francklyn, C.S. (2007) Kinetic Discrimination proofreading of tRNA identity by the conserved motif 2 loop of a class II aminoacyl-tRNA Synthetase. Molecular Cell 25:531-542.
Minajigi, A. & Francklyn, C.S. (2008) RNA assisted catalysis in a protein enzyme: the 2´ hydroxyl of tRNAThr A76 promotes aminoacylation by threonyl-tRNA synthetase . Proc. Natl. Acad. Sci. USA, in press.
Enzyme Paralogs: Alternative Functions with a Common Catalytic Fold
Qui, H., Dong, J., Ha, C., Francklyn, C.S., Hinnebusch, A.G. (2001) The tRNA binding in GCN2 contains a dimerization domain that interacts with the kinase domain and is required for activation by uncharged tRNA. EMBO J.20: 1425-1438.
Champagne, K.S., Sissler, M., Larrabee, Y*., Doublie, S., and Francklyn, C.S. (2005) Activation of the hetero-octameric ATP phosphoribosyltransferase through subunint interface rearrangement by a tRNA synthetase paralog. Journal of Biological Chemistry. 280(40):34096-104.
Champagne, K.S., Piscitelli, E*., and Francklyn, C.S. (2006) Substrate Recognition by the Hetero-octameric ATP phosphoribosyltransferase from Lactococcus lactis. Biochemistry. 45(50) 14933-14943.
Nuclear Receptor Structure and Function in Cancer
Chris Francklyn and former CMB graduate Anand Minajigi.
Puffenberger EG, Jinks RN, Sougnez C, Cibulskis K, Willert RA, Achilly NP, Cassidy RP, Fiorentini CJ, Heiken KF, Lawrence JJ, Mahoney MH, Miller CJ, Nair DT, Politi KA, Worcester KN, Setton RA, Dipiazza R, Sherman EA, Eastman JT, Francklyn C , Robey-Bond S, Rider NL, Gabriel S, Morton DH, Strauss KA. Genetic mapping and exome sequencing identify variants associated with five novel diseases. PLoS One. 2012;7(1):e28936. Epub 2012 Jan 17
Farris M, Lague A, Manuelyan Z, Statnekov J, Francklyn C Altered nuclear cofactor switching in retinoic-resistant variants of the PML-RARα oncoprotein of acute promyelocytic leukemia. Proteins. 2012 Apr;80(4):1095-109. doi: 10.1002/prot.24010. Epub 2012 Jan 7.
Huang W, Bushnell EA, Francklyn CS , Gauld JW. The α-amino group of the threonine substrate as the general base during tRNA aminoacylation: a new version of substrate-assisted catalysis predicted by hybrid DFT. J Phys Chem A. 2011 Nov 17;115(45):13050-60. Epub 2011 Sep 26
Pasman Z, Robey-Bond S, Mirando AC, Smith GJ, Lague A, Francklyn CS. Substrate specificity and catalysis by the editing active site of Alanyl-tRNA synthetase from Escherichia coli. Biochemistry. 2011 Mar 8;50(9):1474-82. Epub 2011 Jan 31.
Minajigi A, Deng B, Francklyn CS .Fidelity escape by the unnatural amino acid β-hydroxynorvaline: an efficient substrate for Escherichia coli threonyl-tRNA synthetase with toxic effects on growth. Biochemistry. 2011 Feb 15;50(6):1101-9. Epub 2011 Jan 24.
Minajigi A, Francklyn CS . Aminoacyl transfer rate dictates choice of editing pathway in threonyl-tRNA synthetase. J Biol Chem. 2010 Jul 30;285(31):23810-7. Epub 2010 May 26.
Guth E, Farris M, Bovee M, Francklyn CS. Asymmetric amino acid activation by class II histidyl-tRNA synthetase from Escherichia coli. J Biol Chem. 2009 Jul 31;284(31):20753-62.
Minajigi A, Francklyn CS. RNA-assisted catalysis in a protein enzyme: The 2′-hydroxyl of tRNA(Thr) A76 promotes aminoacylation by threonyl-tRNA synthetase. Proc Natl Acad Sci U S A. 2008 Nov 18;105(46):17748-53.
Francklyn CS. DNA polymerases and aminoacyl-tRNA synthetases: shared mechanisms for ensuring the fidelity of gene expression. Biochemistry. 2008 Nov 11;47(45):11695-703.
Guth EC, Francklyn CS. Kinetic discrimination of tRNA identity by the conserved motif 2 loop of a class II aminoacyl-tRNA synthetase. Mol Cell. 2007 Feb 23;25(4):531-42.