Figure 3
From: Preparation of cell-permeable Cre recombinase by expressed protein ligation
Activity of Cre-R9 remains intact after EPL. Linearized pGEM-T (LoxP Kmr LoxP) is 4,096 bp in length and contains a LoxP Kmr LoxP at one end. Cre-mediated recombination between two LoxP sites results in a linear (3,000 bp) pGEM-T (LoxP) and a circular (1,096 bp) LoxP-Kmr. Cre and the semisynthetic Cre-R9 (ssCre-R9) were incubated with the linearized pGEM-T (LoxP Kmr LoxP) at 37°C for 1 h. After isolated from proteins by phenol extraction, DNA was analyzed by agarose gel electrophoresis. M, Lambda DNA digested with EcoRI and HindIII.