5f64 is a 4 chain structure with sequence from Shigella flexneri 2a str. 2457t. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance.
[EVGA_SHIFL] Member of the two-component regulatory system EvgS/EvgA. Regulates the expression of emrKY operon and yfdX. Seems also to control expression of at least one other multidrug efflux operon (By similarity).