Cas protein composition of immunopurified Csa, Cst, and Cmr complexes. (A) Cas proteins identified by tandem mass spectrometric analysis of Csa (green), Cst (yellow), Cmr (blue) immunoprecipitated complexes are indicated by a check mark. Some Cas proteins predicted to be part of a complex but not identified by mass spectrometry are also listed. (B) Silver-stained SDS-polyacrylamide gels of Csa (Csa2), Cst (Cst2), and Cmr (Cmr2) immunoprecipitated pellets with preimmune (PI) or immune (I) antibodies as labeled. Cas proteins identified by tandem mass spectrometry are indicated based on expected molecular weight. The antigens are labeled in bold. Cas proteins identified by mass spectrometry that do not correlate to a visible band are marked with an asterisk. M is the protein standard in kilodaltons (kDa).
