ATP is an essential energy currency in our cells, just like electricity to our home. We use a wide variety of electrical appliances in our daily life. Similarly, our cells employ various ATPases, which utilize energy from ATP hydrolysis to remodel their substrate molecules. The AAA-family ATPases are powerful nano-scale molecular machines that can remodel macromolecules, such as proteins and DNA. Their functions range from protein translocation and degradation, to complex assembly and disassembly.