The catalytic domain of topological knot tRNA methyltransferase (TrmH) discriminates between substrate tRNA and nonsubstrate tRNA via an induced-fit process

Background: Topologically knotted tRNA methyltransferases specifically recognize substrate tRNA. Results: Site-directed mutagenesis studies, chimeric protein analysis, and pre-steady state kinetics clarify the tRNA recognition sites of TrmH. Conclusion: The N- and C-terminal regions function in the initial binding process, and substrate tRNA is discriminated by the catalytic domain in an induced-fit process. Significance: Study of how proteins recognize RNA is crucial for understanding RNA maturation processes.