Detection of the subcellular localization of MtsA in S. iniae HD-1 by western blotting. (A) The cellular fractions of S. iniae HD-1 and rabbit anti-MtsA antibodies were used for the western-blot assay. Lane 1, S. iniae HD-1 lysate; lane 2, soluble fraction of cells; lane 3, particulate fraction of cells; lane 4, cell wall extracts; lane 5, protoplast; lane 6, particulate fraction of protoplasts; and lane 7, soluble fraction of protoplasts. (B) Surface exposure of MtsA. Cells (lanes 1 and 2), cell wall extracts (lanes 3 and 4), and protoplasts (lanes 5 and 6) of S. iniae HD-1 were treated with proteinase K and analyzed by western blotting. Lanes 1, 3 and 5 show the untreated control, while lanes 2, 4 and 6 show samples treated with proteinase K for 1 h.