Figure 5. The AAA+ domains of DnaC and DnaA interact in a nucleotide-dependent manner.

(A) Co-precipitation of DnaC_AAA+ by domains III and IV of Aquifex aeolicus DnaA fused to maltose binding protein (MBP-DnaA_III–IV). The positions for MBP-DnaA_III–IV, untagged DnaA_III–IV, and DnaC_AAA+ on the SDS PAGE gel are indicated. Apo - no nucleotide was added to reaction conditions; “ISM mutant” - double mutant F121D/Y165D. Free MBP present in lane 9 resulted from incomplete separation of the protein from the DnaC_AAA+ ISM mutant during purification (see Sup. Material). (B) Quantitation of the results presented in (A). Experiments for each condition were repeated three times and averaged. Error bars represent the variance between experiments.