Structure of gyrase homologs: (a) The structural diagram of RCC1, PDB entry 1A12 chain A. Each blade is shown in a different color and β-strands in the third blade are labeled. Sequence conservation in (b) GyrA/ParC and (c) RCC1 mapped onto the structure of the third blade in RCC1 are rainbow colored from low conservation (dark blue) to high conservation (red).