Fig. 5. Sequence requirements for Lab, Lab/Exd and Lab/exd/Hth binding to EVIII. (A) Sequences of the mutated EVIII oligonucleotides tested for band-shift experiments with Lab and the co-factors Exd and Hth. Positions of each nucleotide within the Lab/Exd sequence are numbered 1 to 10, and orientations of each binding site are indicated (arrowheads). The two central nucleotides of the Lab/Exd-binding site are highlighted in yellow, while mutated nucleotides are in red. (B) Band shift experiments with the control wild-type and the mutated versions of the EVIII oligonucleotide listed in A. The identity of the oligonucleotide used is indicated below the gel. For each gel, the first two lanes correspond to the probe, alone (first lane) or with the rabbit reticulocyte lysate (second lane). The next three lanes are in the same order: Lab alone (lanes 3, 8, 13, 18, 23, 28, 33, 38, 43 and 48), Lab with Exd (4, 9, 14, 19, 24, 29, 34, 39, 44 and 49) and Lab with Exd and Hth (lanes 5, 10, 15, 20, 25, 30, 35, 40, 45 and 50).