Relationships between PEC assembly and MOS1 concentration. EMSAs were performed with 250 nM of short-PC labeled ITR, excepted in lane 8, and various amount of purified MBP-MOS1, ranging from 0 to 2.5 µM. Lane 1: no MOS1, lane 2: 50 nM, lane 3: 100 nM, lane 4: 250 nM, lane 5: 500 nM, lane 6: 1 µM, lane 7: 2.5 µM. Lane 8: 2.5 µM of short-PC and 2.5 µM MOS1. Short-PC: short pre-cleaved ITR. B. Relationships between PEC assembly and ITR concentration. Left panel: EMSAs were performed with various amount of short-PC labeled ITR, and 100 nM of MOS1. Lane 1: 5 nM ITR, lane 2: 10 nM, lane 3: 50 nM, lane 4: 100 nM, lane 5: 150 nM, lane 6: 250 nM, lane 7: 500 nM, lane 8: 750 nM, lane 9: 1 µM. Right panel: the amount of ITR in the PEC (nM) was plotted against the concentration of free ITR (nM). The maximum amount of bound ITR obtainable for MOS1 concentration of 100 nM, Bmax, is indicated (dotted line). Short-PC: short pre-cleaved ITR.