Book Viewer

Short Contents | Full Contents | Other books @ NCBI

Modern Genetic Analysis Chapter 14. Regulation of Gene Transcription
Metabolic Pathways

Coordinate control of genes through operon-level regulation in bacteria and bacteriophages is widespread. In the preceding section, we looked at examples of regulation of pathways for the metabolism of specific sugars. In fact, most coordinated gene function in prokaryotes acts through operon mechanisms. For example, enzymes in many biosynthetic pathways are encoded by clustered genes organized into operons, complete with multigenic mRNAs. Furthermore, in cases where the sequence of catalytic activity is known, there is a remarkable congruence between the sequence of genes on the chromosome and the sequence in which their products act in the metabolic pathway. This congruence is strikingly illustrated by the organization of the tryptophan operon in E. coli (Figure 14-18).

MESSAGE
In prokaryotes, genes that encode enzymes that are in the same metabolic pathways are generally organized into operons.

© 1999 by W. H. Freeman and Company. All rights reserved.