RNA-BINDING PROPERTIES OF RIBOSOMAL-PROTEIN L1 FROM THERMUS-THERMOPHILUS

Several proteolytic fragments of ribosomal protein L1 from Thermus the rmophilus were obtained. The binding of intact protein L1 and its prot eolytic fragments to 23S ribosomal RNA has been studied. The first eig ht N-terminal amino acid residues of the protein are important for the RNA binding; removal of these acids results in a significant decrease in the RNA-binding capacity of protein L1. Cleavage of the polypeptid e chain between residues 36 and 37 completely abolishes the RNA bindin g. Comparison of the data obtained from the recently determined spatia l structure of protein L1 clarifies the nature of the interactions tha t control specific and strong association of protein L1 with 23S rRNA.