Pro-Blue-stained SDS-PAGE profiles of subcellular fractions prepared from cells grown anaerobically with fumarate as the electron acceptor. Lanes 1, 3, 5, and 7, MR-1; lanes, 2, 4, 6, and 8, MTRB1. The lanes were loaded with 25 μg of protein from each of the following subcellular fractions: CM (lanes 1 and 2), IM (lanes 3 and 4), OM (lanes 5 and 6), and soluble fraction (lanes 7 and 8). The numbers on the left indicate the migration positions and molecular masses of TriChromRanger prestained protein markers (Pierce) in lane M.