The Complexity of Protein Biosynthesis

The protein biosynthetic mechanism and its attendant regulatory controls are immensely complex, and the scientific literature about them is voluminous and intricate. It is not our intent—nor is it possible in one chapter—to cover all details of the biosynthetic process. Rather, in this chapter we shall emphasize the regulatory controls of protein biosynthesis. However, such a consideration requires review of some details of the biosynthetic pathways, so that the nature of the regulatory controls can be appreciated. For more detailed information, the reader is referred to the various reviews and books on the subject (e.g., Weiss-bach and Pestka, 1977 Vogel, 1977 Nienhuis and Benz, 1977 Chan, et al., 1977 Busch, et al., 1976 Goldberger, 1979). 

The mechanisms that regulate protein biosynthesis must be such that appropriate concentrations and types of enzymes can be synthesized in response to extracellular conditions. Furthermore, the protein biosynthetic mechanism is of such paramount importance to life, and so complex, that we would expect multiple controls to exist. This expectation is completely justified—such controls being found at all levels of information transfer required in the protein biosynthetic mechanism. In order to maintain a balance between the component parts, the regulatory mechanisms must control the rates of protein synthesis, utilization, and degradation. Of course, it need hardly be pointed out that, while nucleic acids provide the information for protein synthesis, enzymes mediate the biosynthetic processes themselves. 

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