We present the DNA sequence and plant-tumor transcription pattern of some 2400 base pairs from the right border region of pTi T37 DNA from the virulent Agrobacterium tumefaciens strain T37. This region includes the entire transcription unit encompassing the nopaline synthase gene, together with parts of other transcription units. The strategy used to determine the sequence also produced two opposing series of defined, asymmetric deletions across the target DNA region, some of which may serve future purposes in the exploitation of this sequence, which is known to be expressed in a wide variety of host plant tissues.