%0 Journal Article %A Klapwijk, P. M. %A Oudshoorn, M. %A Schilperoort, R. A. %T Inducible Permease Involved in the Uptake of Octopine, Lysopine and Octopinic Acid by Agrobacterium tumefaciens Strains Carrying Virulence-associated Plasmids %D 1977 %J Microbiology, %V 102 %N 1 %P 1-11 %@ 1465-2080 %R https://doi.org/10.1099/00221287-102-1-1 %I Microbiology Society, %X [3H]Octopine is transported by ‘octopine’ strains of Agrobacterium tumefaciens after induction by either octopine, lysopine or octopinic acid and by ‘nopaline’ strains after induction by nopaline. The analogues noroctopine, homooctopine and desmethylhomo-octopine had no inducing effect. Lysopine and octopinic acid showed a competitive influence on octopine uptake, as would be expected if there was one permease for all three compounds. The Michaelis-Menten constant for octopine transport was about 1·5 μ m. A sharp decline in transport activity was observed at pH values below 6·0. Evidence is provided that the octopine permease gene (uadB) and the accessory regulator gene (uadR) are carried by TI plasmids. %U https://www.microbiologyresearch.org/content/journal/micro/10.1099/00221287-102-1-1