Fig. 3

Assessing the specificity of MT13-C. a Activity profiling of MT13-C. An array of peptides corresponding to the eEF1A N terminus harboring single amino acid substitutions was incubated with MT13-C and [³H]-AdoMet, whereafter methylation was visualized by fluorography. The sequence of eEF1A (positions 2–8) is displayed on the horizontal axis and the residues introduced at the corresponding positions are indicated on the vertical axis. b Sequence motif logo plot representation of MT13-C substrate sequence preference as shown in a. c Evaluation of candidate MT13-C substrates. Top panel, outline of a peptide array containing candidate substrates (1–49) as well as the location of peptides corresponding to eEF1A without the iMet (positive control (PC)) and with retained iMet (negative control (NC)). Bottom panel, fluorograph of membrane incubated with MT13-C and [³H]-AdoMet. All peptide sequences are listed in Supplementary Data 2. d Evaluation of cell extracts as substrates for MT13-C. Top, protein extracts from HAP-1 WT and METTL13 KO cells were incubated with MT13-C as indicated, and methylation of size-separated proteins was visualized by fluorography. Bottom, western blot (WB) against eEF1A of membrane used for fluorography in upper panel. An uncropped image of the blot is shown in Supplementary Fig. 6b