PURIFICATION AND PROPERTIES OF THE HETEROGENEOUS SUBUNITS OF ELONGATION-FACTOR EF-1 FROM GUERIN EPITHELIOMA CELLS

Elongation factor EF-1 from Guerin epithelioma was separated into two subunit forms EF-1A and EF-1B by chromatography in the presence of 25% glycerol, successively on CM-Sephadex and DEAE - Sephadex. It was shown that EF-1A is a thermolabile, single polypeptide which catalyses the binding of aminoacyl - tRNA to ribosomes, similarly as eukaryotic EF-1-alpha or prokaryotic EF-Tu. EF-1B was characterized as a complex composed of at least two polypeptides. One of them is EF-1A, the other EF-1C, which stimulates EF-IA activity and protects this elongation factor from thermal inactivation.