Structural and functional analysis of a putative gene cluster for palatinose transport on the linear chromosome of Agrobacterium tumefaciens MAFF301001

We identified a putative pal gene cluster (palR, palE, palF, palG, palK, palA, and palB) in the plant-tumorigenic bacterium Agrobacterium tumefaciens MAFF301001; by sequencing analyses, this cluster was found to be involved in palatinose transport, and its functional importance was revealed by mutational analyses. The pal gene products were highly homologous to those of putative trehalose/maltose ABC-type transport systems but were not essential to bacterial growth on trehalose. Insertion mutations in the palK and palE genes showed the necessity of these genes for bacterial growth and chemotaxis with palatinose as the carbon source, but no inhibition of tumorigenesis was observed. Growth on trehalose and maltose was not influenced by the mutations.