Abstract
The protein biosynthetic machinery, consisting of numerous protein and nucleic acid components, is among the most complex systems in the mammalian cell (reviewed in Merrick & Hershey, 1996). Much of what we know about the mechanism of translation and of the macromolecules involved in the process has come from extensive purification and reconstitution of the system in vitro. However, until recently, relatively little attention has been given to how these several hundred macromolecules interact and function within the environment of the cell. Nevertheless, the in vitro studies have been invaluable for identifying components required for the translation process and for elucidating their likely mode of action.