Figure 3. The N‐terminal region of FRH is unstructured in the absence of FRQ.

1. Comparison of the FRH N‐terminus (large‐cell structure, magenta) to that of Mtr4 (green) aligned on their RecA domains. Only the additional elements of FRH are shown (cyan). The FRH N‐terminal extension has little ordered secondary structure, although regions 143–147 and 129–135 form small turns that interact with the helicase core.
2. The very N‐terminus of FRH extends away from the RecA‐2 domain to interact with a symmetry‐related molecule in the crystal (below), whereas the Mtr4 N‐terminus turns back to form an outer β‐strand. Center panel shows the crystal contacts, with close‐ups for each region highlighted as insets on the left and right.