Genetic regions of Pseudomonas aureofaciens strain 211 involved in nopaline catabolism

Abstract

A DNA fragment from the nopaline catabolism region of the Ti plasmid of Agrobacterium tumefaciens showed no detectable homology to the total DNA of several nopaline-utilizing strains of Pseudomonas spp. From one of these pseudomonads, Pseudomonas aureofaciens strain 211, mutants defective in the catabolism of nopaline but not arginine, have been obtained by mutagenesis with transposon Tn5, and also with TnV using a new suicide plasmid vector. The DNA fragment bearing the TnV insertion has been cloned and found to hybridize with DNA of every pseudomonad tested, independently of the capacity to utilize nopaline, but not with Agrobacterium DNA. In a separate experiment, nonmutagenized DNA of strain 211 was cloned in a cosmid vector. Transfer of one of these clones to Pseudomonas putida strain KT2440 conferred on the recipient the capacity for nopaline utilization. However, this cosmid clone was only partially functional, since it did not complement a TnV mutant.