Structure and function of a conserved DNA region coding for tartrate utilization in Agrobacterium vitis

Three tartrate utilization regions from Agrobacterium vitis strains involve d in host specificity have been compared, to clearly define the borders of these regions and eventually identify specific sequences that could provide a mechanism of duplication of this region. A 10.8-kb conserved DNA fragmen t called the TAR element, found in different genetic contexts, was defined. A comparison of the two tartrate dehydrogenase genes (ttuC and ttuC') in e ach of the three TAR elements suggests that these genes co-evolve. (C) 1999 Federation of European Microbiological Societies. Published by Elsevier Sc ience B.V. All rights reserved.