HSP70 and ribosomal protein L2: novel 5S rRNA binding proteins in Escherichia coli

A Northwestern analysis of Escherichia coli total proteins with radiolabele d 5S rRNA identified two novel 5S rRNA interacting proteins, a 70 kDa and a 37 kDa protein, and three ribosomal proteins reported on already. The N-te rminal sequencing of the 70 kDa protein separated by SDS-PAGE from the high -salt-washed fraction of crude ribosome led to the discovery of a polypepti de identical in its first 10 amino acid residues to E. coli heat shock prot ein 70, The N-terminal eight amino acid sequence of the 37 kDa protein extr acted from the high-salt-mashed ribosome is identical to that of the riboso mal protein L2, In addition, the interaction of these proteins with 5S rRNA has been confirmed with gel mobility shift assays, (C) 2000 Federation of European Biochemical Societies. Published by Elsevier Science B.V. All righ ts reserved.