Figure 2

Protein multiple sequence alignment across the core histidine motif of selected ELAC/ tRNase Z family members. The ELAC/tRNase Z family members were selected from Saccharomyces cerevisiae (Sce), Schizosaccharomyces pombe (Spo), Arabidopsis thaliana (Ath), Drosophila melanogaster (Dme), Homo sapiens (Has), Escherichia coli (Eco) and Methanothermobacter thermautotrophicum (Mth). The boxed residues in the S. cerevisiae sequence are the amino acids that we mutagenized in our effort to create a ts mutant. 1, S. cerevisiae M535 corresponds to human A541. 2, Y537L is ts. 3, L538K is ts. 4, H542 corresponds to human H548, the position of a prostate cancer associated frameshift. 5, G548 corresponds to G256 of S. cerevisiae PSO2; although PSO2 G256R is a ts mutant [16], TRZ1 G548R is lethal. * denotes identical amino acid, and : /. indicates homologous conservation across species.