EUKARYOTIC INITIATION OF PROTEIN SYNTHESIS

Abstract

This chapter discusses the eukaryotic initiation of protein synthesis. Initiation of eukaryotic protein synthesis occurs with essentially the same components which includes initiator tRNA, mRNA, and small and large ribosomal subunits. In spite of this similarity, the generalized role of eukaryotic initiation factors bears only slight resemblance to IF-1, IF-2, or IF-3. For this reason, the first part of this report will attempt to provide an organizational framework that should give some insight into the number and characteristics of eukaryotic protein synthesis initiation factors. Following this introduction will be a brief presentation of several findings which add new information on the pathway of 80S initiation complex formation. The most important initiation factors, eIF-2, and eIF-3, consist of 3, and probably 9 polypeptide chains respectively, and three, the total daltons of protein committed to eukaryotic protein synthesis initiation is about 1,000,000 compared with the 130,000 daltons of protein required for prokaryotic initiation of protein synthesis.