The translocated virulence protein VirD5 causes DNA damage and mutation during <i>Agrobacterium</i>-mediated transformation of yeast.

Abstract

The soil bacterium <i>Agrobacterium tumefaciens</i> is a preferred gene vector not only for plants but also for fungi. <i>Agrobacterium</i> delivers a small set of virulence proteins into host cells concomitantly with transferred DNA (T-DNA) to support the transformation process. Here, we find that expression of one of these proteins, called VirD5, in yeast host cells causes replication stress and DNA damage. This can result in both genomic rearrangements and local mutations, especially small deletions. Delivery of VirD5 during cocultivation with <i>Agrobacterium</i> led to mutations in the yeast genome that were unlinked to the integration of T-DNA. This load of mutations can be prevented by using a <i>virD5</i> mutant for genome engineering, but this leads to a lower transformation frequency.