FIGURE 4.

Fragmentation pattern of intact wild-type ribosomal protein Rpl12ab and a peptide from the ΔRKM2 mutant protein. Fractions containing Rpl12ab isolated from the LC-MS+ chromatography were subjected to either top down analysis using electron capture dissociation and collisionally activated dissociation of the wild-type protein (panel A) or collisionally activated dissociation of the tryptic N-terminal peptide from the ΔRKM2 protein (panel B, Ref. 11) as described in the legend of Fig. 2 and the “Experimental Procedures” section.