The clustering on the Pseudomonas putida chromosome of genes specifying dissimilatory functions.

Abstract

Two previously demonstrated linkage groups containing genes with catabolic function inPseudomonas putida have been shown to cotransduce with a third cluster of catabolic genes, namely those specifying enzymes of nicotinic acid dissimilation. Thus enzymes of the following dissimilatory pathways are coded by genes clustered in one small (10-15% of the chromosome) genetic region:p-hydroxy-benzoic, quinic, shikimic, benzoic, mandelic, phenylacetic, and nicotinic acids; and histidine, tyrosine and phenylalanine. We propose that this clustering is a consequence of the selection, in natural populations of bacteria, of gene arrangements which permit simultaneous transfer of the genetic determinants of a variety of dissimilatory pathways.