DE-NOVO PURINE NUCLEOTIDE BIOSYNTHESIS

This chapter discusses the recent progress made in understanding de novo purine nucleotide biosynthesis and its regulation in bacteria. A purR-encoded repressor—operator interaction plays a key role in the genetic regulation of purine biosynthesis in E. coli and also appears to be involved in coordinating the expression of genes in related metabolic pathways. The outline of a more complex regulatory system has been described for de novo purine nucleotide synthesis in B. subtilis. These advances have resulted from the cloning and analyses of structural genes encoding the biosynthetic enzymes and the purR regulatory gene from E. coli. The cloning of regulatory genes is essential for a further understanding of the regulation of purine nucleotide biosynthesis in B. subtilis. © 1992 Academic Press Inc.