Structural model of the ATP‐binding domain of the F₁‐β subunit based on analogy to the RecA protein

In contrast to the previous topological model of the ATP binding domain of the F 1 ‐ATPase β subunit based on analogies to those of ras p21 and adenylate kinase, a more consistent model can be constructed with the known structure of the recA protein as a reference. The secondary structure of the F 1 ‐ATPase β subunit predicted from the primary structure agrees well with that of the recA protein. The topology includes a repetitive βα C βαβαβαβ structure where all β strands are parallel and surround the central α C helix above which bound ATP is located. Several residues thought to be located at catalytic site as reported in genetic and chemical labeling work can be consistently positioned in this model.