“…(1984) with some modifications: cells were first grown at 32°C up to an A,,, value of 0.1, during which the plasmid is present at one copy per cell. This was followed by a 55-min thermal shock at 43"C, which allows the overproduction Partial proteolysis of GluRS GluRS was purified as described previously (Lapointe et al 1985), dialyzed against 50 mM Hepes-NaOH, pH 8.0, containing 10 mM 2-mercaptoethanol, 0.2 mM dithiothreitol, and 50% glycerol, and kept at a concentration of about 3 mg/mL at -20°C. Proteases (thermolysin, V8 protease, papain, elastase, chymotrypsin, plasmin, and trypsin) were dissolved at a concentration of 500 pg/mL in 100 mM Tris-HCI, pH 7.5, containing 1 mM 2-mercaptoethanol (Cassio and Waller 1971), and kept at -20°C.…”