Figure 5.

Transcleavage of a heterologous target protein. The structures of the transcleavage assay coexpression plasmids are schematically illustrated. pcI.rpt2-3 expresses the cI repressor containing C1 repeats 2–3 whereas pGST5cahis expresses the indicted C1 fusion protein. The steady state levels of the target cI repressor are shown in the cI Western blot for the coexpression cultures containing pcI.rpt2-3 or the control pcI.Bss and either GST-5ca (5ca), GST-5cainv (inv), or pgst-1λ control vector (C). (−) and (+) indicate uninduced and induced cultures, respectively. Chemifluorescent quantitation of the precursor cI.rpt2-3 is graphically illustrated relative to the control culture. Only the precursor protein is monitored as the cleavage products are rapidly degraded (H. J. Sices and T.M.K., unpublished observations).