Pathway-specific pattern of control of arginine biosynthesis in bacteria.

Udaka, Shigezo (The Institute of Physical and Chemical Research, Komagome, Bunkyo-ku, Tokyo, Japan). Pathway-specific pattern of control of arginine biosynthesis in bacteria. J. Bacteriol. 91:617-621. 1966.-To compare control mechanisms of arginine biosynthesis in various bacteria, activities of several enzymes of the arginine pathway were measured in cells cultivated under repressed and partially derepressed conditions. Nineteen strains of bacteria tested appeared to have two types of pathways, closely related to each other. The partially derepressed levels of enzymes varied from bacterium to bacterium. The degree of inhibition of enzyme 2 (the second of eight enzymes concerned with arginine biosynthesis) and the repressibility of enzymes by arginine also appeared to vary from species to species. On the other hand, enzyme 2 was found to be the site of end-product inhibition only in the bacteria having a particular pathway. These results suggest that the bacteria have their own species-specific control mechanisms and that there is a pathway-specific pattern of control in arginine biosynthesis. The implications of the results are discussed from the viewpoint of evolution of control mechanisms.