Precipitates were resuspended in 50 mM Tris/HCl, pH 7.5 and 250 mM NaCl and transferred into new tubes. The supernatant was subjected to immunoprecipitation overnight at 4°C using 5 μg of monoclonal anti-GFP antibody (clones 7.1 and 13.1; Roche) cross-linked to protein A–Sepharose with DMP. …