Aminoacylation and misaminoacylation activities of M. mobile LeuRSs that contain hybrid CP1 domains. Aminoacylation of 4 μM tRNALeu in presence of (A) 21 μM [3H]leucine (318 μCi/mL), (B) 21 μM [3H]isoleucine (166 μCi/mL), (C) 20.2 μM [35S]methionine (115 μCi/mL), and (D) 20 μM [14C]valine (259 μCi/mL). Symbols used are as follows: ■, MmLeuRS (Mm); ▲, MmLeuRS/CP1Leu (Mm/CP1Leu); ▼, MmLeuRS/CP1Ile (Mm/CP1Ile); and ◆, MmLeuRS/CP1Val (Mm/CP1Val). Error bars represent SDs from triplicated reactions.