Change in the location of amylomaltase produced by mutation in Escherichia coli.

The utilization of sugars, for example lactose or maltose, can take place in E8cherichia coli only in the presence of two catalytic systems, namely permease and enzymes catalysing the breakdown of the sugars within the cell (Cohen & Monod, 1957). The present paper reports mutants that are not capable of utilizing maltose, although amylomaltase is present in the cell. The results, however, indicate that it is not crypticity to maltose that causes incapacity for utilization but a change in location that is connected with the binding of amylomaltase in the cell structure. a-Glucosidase in an inactive form bound to the cell structures of Saccharomyce8 cerevi8iae was found by Robertson & Halvorson (1957), and a similar observation was made by Axelrod (1962) in Saccharomycea oviformis. In the latter case it was shown that ribonuclease solubilizes bound aglucosidase from the cell structures. A preliminary account of this work was presented at the Third Congress of the Czechoslovak Biochemical Society, Olomouc, Czechoslovakia, 15 July 1963.