Association of L29 protein with ribosomes isolated from etioplasts and chloroplasts. L2, L21, and L29 in ribosomes from MC and BSC of etiolated and greening plants. (A) Immunoblot for ribosomal protein L29 in ribosomes isolated from purified etioplasts (E) and from chloroplasts (Chl) of dark-grown plants illuminated for 10 hr (18). (B) Representative immunoblots for ribosomal proteins L2, L21, and L29. Ribosomes were isolated from MC of etiolated leaves (EM), from BSC of etiolated leaves (EBS), from MC and BSC of dark-grown plants illuminated for 10 hr (LM and LBS, respectively) (7, 18). The lanes were loaded with equal amounts of rRNA.