Figure 6.

BB0646 is a detergent phase associated protein that is not surface localized. (A) Phase partitioning analysis of BB0646. Whole cell lysates from ML23 and DS102 were subjected to Triton X-114 phase partitioning and following exposure to high salt (i.e., 1M NaCl, 1M Tris, or 0.1 M Na₂CO₃). Detergent and aqueous phases were compared to whole cell lysates by Western immunoblotting with BB0646 antiserum. Detergent and aqueous phase proteins from 10⁸ whole cell equivalents were loaded into each lane. An arrow indicates the position of BB0646. Numbers on the left refer to the molecular mass of protein makers (in kDa). (B) Localization of BB0646. Strain ML23 was incubated with Proteinase K to assess whether BB0646 was surface exposed. Controls were either incubated in PBS alone (not treated; NT), permeabilized with Triton X-100 (TX-100), treated with Proteinase K alone (PK), or incubated with Proteinase K following exposure to Triton X-100 (TX-100 + PK). Following SDS-PAGE, samples were immunoblotted and probed with antisera against FlaB, P66, and BB0646 (as indicated on the right). Numbers on the left refer to the molecular mass of protein makers (in kDa).