Relationship between elongation factor 1- and elongation factor 2-dependent guanosine triphosphatase activities of ribosomes. Inhibition of both activities by ricin

Abstract

The elongation factor 1- and elongation factor 2-dependent GTPase (guanosine triphosphatase) activities of ribosomes are inhibited by ricin, a toxic protein known to inactivate the 60S ribosomal subunit. It is suggested that also in eukaryotic ribosomes a “GTPase site’, located on the larger subunit, is common to the two elongation factors.