Purification of the Cdv proteins from M. sedula.

(A) Schematic representation of the proteins encoded by the cdv gene cluster from M. sedula. The black boxes correspond to protein-protein interaction motifs, i.e the CdvB-binding site of CdvA which interacts with the WH domain of CdvB and the MIM2 of CdvB that binds the MIT domain of CdvC [10], [25]. (B) Recombinant full length CdvA from M. sedula was separated by SDS-PAGE (12%) and stained with Coomassie blue. Values on the left indicate molecular weights of the marker proteins. (C) Elution profile of CdvB from a Superdex 200 SEC column. The inset shows the SDS page band of purified CdvB. (D) The SEC profile (Superose 6) of CdvC (50 µM) and MALLS analysis; the inset shows the SDS-page band of CdvC. Protein elution from the column was monitored by refractometry (solid line) and the molar mass was determined by static light scattering (dots). Three different populations were observed. Pic 1: 530±50 kDa; Pic 2: 130±20 kDa; Pic 3: 40±5 kDa. (E) SEC elution profile (Superose 6) of CdvC (180 µM). Inset: Fractions corresponding to the peak separated by SDS-PAGE. The columns were standardized with the following molecular weights markers : blue dextran (2.106 kDa); tyroglobuline (670 kDa); ferritine (440 kDa); catalase (232 kDa); bovine serum albumin (67 kDa) and ribonuclease A (13.7 kDa).