FIG. 1.

2-D protein arrays of A. ferrooxidans grown on ferrous iron or elemental sulfur. Total proteins from cells grown in the presence of [³⁵S]methionine and ferrous iron (A) or elemental sulfur (B) were separated by 2-D NEPHGE with a pH gradient between 3.0 (right side of the gel) and 10.0 (left side of the gel). Spots were detected by autoradiography. Numbered spots are those characterized in this study. As internal controls for proteins that do not greatly change their levels of synthesis during growth under these conditions, we used GroEL (g), DnaK (d,) and Omp40 proteins previously identified in our laboratory (14, 42). Positions of molecular mass standards (in kilodaltons) are given on the left.