Structure Function Analysis of human m1A58 tRNA Methyltransferase

• Applicant: Dr. Nadine Czudnochowski
• Subject Area: Structural Biology
• Term: from 2011 to 2013
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 211216904

Specific RNA modifications occur in all cellular RNAs, yet the basis for dynamic selection of the target site is known in only a few special cases. Methylation of A58 in the TPsiC-loop of tRNAs is a highly conserved modification that is found throughout all kingdoms of life. Methylation of A58 in human tRNA3Lys is reported to be required for normal HIV-1 replication. If so, human m1A58 methyltransferase (m1A58MT) could provide an important HIV drug target. I propose to determine the basis for specificity of human m1A58MT for this key base in tRNA3Lys at the level of atomic structure. I aim to obtain crystal-structures of the tRNA3Lys-enzyme-cofactor analogue complex. By comparison with the enzyme-cofactor and free tRNA structures I hope to elucidate the deformation of tRNA necessary to catalyze A58 methylation. By determining the enzymatic parameters toward the cofactor S-adenosyl-L-methionine and tRNA and the affinity of the tRNA-protein interaction I will define what would be required of an inhibitor to challenge HIV replication. Finally I will use RNAi-mediated gene knockdown of m1A58MT to calibrate its role for reverse transcription of HIV-1.

• DFG Programme: Research Fellowships
• International Connection: USA
• Host: Professor Dr. Robert Stroud