FIG. 1.
Expression and dimerization of CRPMt and CRPBCG. (A) CRPMt and CRPBCG were overexpressed in E. coli and purified with a HisTrap column (Amersham Biosciences). Lanes: M, broad-range protein molecular weight markers (Promega); 1 to 3, CRPMt; 4 to 6, CRPBCG. Lanes 1 and 4 are lysates of uninduced bacteria; lanes 2 and 5 are lysates of bacteria induced with IPTG; lanes 3 and 6 are purified proteins. (B) Glutaraldehyde cross-linking of purified CRPMt and CRPBCG analyzed by Western blotting. Lanes: M, MagicMark XP Western protein standards (Invitrogen); 1 and 2, CRPMt; 3 and 4, CRPBCG. Proteins in lanes 2 and 4 were cross-linked with glutaraldehyde. (C) Dimerization in bacterial lysates of M. tuberculosis (lane 1) and M. bovis BCG (lane 2) analyzed by Western blotting. Lane M, MagicMark XP Western protein standards. Note that the overexpressed proteins in panel B contain a His tag of about 4.4 kDa. Therefore, the antiserum-recognized bands in panel B and panel C differ in size.