Figure 2.

MFP1 is associated with thylakoid membranes. (A) N-terminal sequence of AtMFP1. The predicted transit peptide for chloroplast import is underlined with a thin line. The predicted signal sequence for thylakoid import is underlined with a thick line. The twin arginine motif is marked in bold. The two predicted cleavage sites are indicated by arrowheads. The two hydrophobic domains previously identified are shaded in gray. (B–D) Fractionation of tobacco leaf chloroplasts. (B) Immunoblot probed with anti-Cytochrome f. (C) Immunoblot with anti-OEC33. (D) Immunoblot with the anti-LeMFP1 antibody 288. Total, total protein extract from tobacco leaves; Chl, total chloroplast protein; Stro, stroma and envelope fraction; Thy, thylakoid fraction; Lum, lumenal fraction; Int, internal membrane fraction; Per, peripheral protein fraction. Molecular masses are indicated on the right. (E) High-salt and high-pH washes of thylakoid fraction. (Top) Immunoblot probed with anti-LeMFP1 antibody 288. (Bottom) Immunoblot probed with anti-OEC33.