Rings in the Extreme: PCNA Interactions and Adaptations in the Archaea

Figure 8

Comparison of the binding pockets of SsoPCNA 1 and 2. The PCNA2 subunit (blue) is superimposed on the PCNA1 subunit of 2IZO (green) to demonstrate that the typical binding motif of Fen1 (magenta, stick representation) cannot be accommodated within the binding pocket of PCNA2 due to steric hindrance [9]. The double proline motif of PCNA2 responsible for the blocking shift in the IDCL is indicated.