FIG. 6.

Gel shift assay revealing binding of a 299-amino-acid recombinant protein fragment of XynR containing the HTH DNA binding domain (Fig. 2) to a ³²P-dCTP-labeled 141-bp DNA fragment (residues 6520 to 6661) containing the transcriptional start site identified for the xynABD transcript by Northern blot analysis and primer extension analysis (Fig. 4 and 5). As the concentration of the recombinant XynR polypeptide was increased, there was a concomitant decrease in the amount of free DNA. Samples were electrophoresed on 8% (wt/vol) polyacrylamide gels.