Physical and Functional Heterogeneity of E. coli Ribosomes

An unexpected egree of heterogeneity for the ribosomal proteins of E. coli was initially demon-strated by Waller (1964). Definitive verification of the multiplicity of ribosomal proteins has been obtained in several laboratories through the purification and characterization f the individual proteins (Kaltschmidt et al., 1967; Fogel and Sypherd, 1968; Moore et al., 1968; Hardy et al.,