FIG. 5.

Western blot of LF-agarose affinity-purified LbpB and LbpA from total membranes of Fe-starved FA6815 (LbpB⁺ LbpA⁺) (lanes A and D), FA6985 (LbpB⁺ LbpA⁻) (lanes B and E), and FA6986 (LbpB⁻ LbpA⁺) (lanes C and F). The blot was probed with antibodies to LbpA and then LbpB. The anti-LbpB antibody used here was raised against an LbpB His-tagged fusion protein. The 66-kDa band present in lanes A and B was recognized by antiserum elicited against full-length recombinant LbpB but not against an LbpB-specific peptide (Fig. 3 and data not shown). This protein band probably represents a breakdown product of holo-LbpB. Lanes A to C, total membranes (TM); lanes D to F, LF-agarose affinity-purified proteins. MW, molecular weight in thousands.