Positions of inteins and spliceosomal introns along the protein sequence (panel A) and in the structure of the replication factor C (panel B). Panel A shows the conservation profile of the RFC protein (see figure 1 for details). The positions of inteins are indicated as blue dots with arrows and positions of spliceosomal introns are green dots without arrows. Panel B shows the structure of the Archaeoglobus fulgidus replication factor C (PDB ID: 2CHV) colored according to sequence conservation. The arrows indicate intein insertion site "a" between Lys51 and THR52, "b" between Ala76 and Ser77, and "c" between Ser138 and Cys139 (all of these six amino acids are shown as space-filled model). All three intein insertion sites are conserved within the host protein.
Swithers et al. BMC Evolutionary Biology 2009 9:303 doi:10.1186/1471-2148-9-303