EFFLUX TRANSPORT OF 3-KETOGLUCOSE 1-PHOSPHATE IN A GLUCOSE 1-PHOSPHATE-NEGATIVE MUTANT OF AGROBACTERIUM TUMEFACIENS

Abstract

Efflux transport reaction for 3-ketoglucose 1-phosphate (3KG-1-P) was investigated with a strain of Agrobacterium tumefaciens M-24 which is a mutant unable to metabolize 3KG-1-P. The efflux transport might be concluded to consist of two systems; a shaking-activated system and an influx transport-dependent system.
As one of efflux transport systems, a novel system, which is revealed by physical treatment of shaking, was proved and designated as "shaking-activated" efflux transport system. The transport system was temperature-dependent and required an activation energy of 4, 600 cal/mol. Potassium cyanide and 2, 4-dinitrophenol did not show any inhibitory effect on the efflux reaction. Therefore, this transport might be energy-independent. From the observations obtained here, mechanism of the shaking-activated efflux reaction was discussed. As another efflux transport system, a system requiring a transport reaction of 3KG-1-P infflux, which is energy-dependent, was suggested.