Western blot analysis of the three full length CipA variants. Supernatants of CipA-expressing recombinant C. acetobutylicum strains (CipA_BB2, CipA_DNA2.0 and CipAnative) were TCA precipitated and concentrated 200-fold. ANTI-FLAG M2 monoclonal antibody-horseradish peroxidise conjugate (Sigma) was used to detect the Flag-tagged CipA proteins. Expected molecular masses are indicated by red arrows. M, ColorPlus Prestained Protein Ladder (10–230 kDa; New England Biolabs), Flag, N-Flag-Bap control protein (50 kDa, 50 ng/lane; Sigma).