FIG. 8.

Membrane insertion of truncated H3L proteins. (A) Hydrophilicity plot of H3L protein. Bars beneath the plot, full-length H3L protein, an N-terminal (NT) truncation, a C-terminal (CT) truncation, and a C-terminal peptide. (B) Insertion of truncated H3L proteins into membranes. Transcription/translation in the presence or absence of microsomal membranes and analysis of supernatant and pellet fractions by SDS-PAGE and autoradiography were carried out as described in the legend to Fig. 6. Lane 1, no DNA was added to the reaction mixture; lanes 2 to 5, the full-length (FL) protein was synthesized; lanes 6 to 8, the C-terminal truncated species (CTr) was synthesized; lanes 9 to 11, the N-terminal truncated species (NTr) was synthesized. Soluble (S) and pellet (P) fractions were analyzed by SDS-PAGE and autoradiography. (C) Insertion of a C-terminal peptide (CT pep) into membranes. Transcription/translation reactions in the absence or presence of microsomal membranes were carried out using a template encoding the C-terminal peptide. Where indicated (+), proteinase K treatment was carried out after the separation of supernatant and pellet fractions. Masses and positions of markers are indicated at the left.