Localising the promoter at the junction cassettes 20 and 21 in the Vibrio sp . DAT722 array. The diagrammatic representation of this area of the array indicates cassette boundaries and PCR primer locations. The putative promoter is highlighted in yellow above the sequence alignment comparing the cassette junctions of the first 21 cassettes in the array. The cassette number within the gene cassette array is shown in the left-hand column. Homology with the -35 area of the cassette 20/21 promoter is shown in bold. Shine-Dalgarno sequences are shown, where they occur, in green. ORFs contained within each gene cassette are shown underlined.