This invention provides an isolated mutant atpE protein and departing from said mutant atpE protein the identification of an ATPase binding domain. This invention also provides related nucleic acids, vectors, host cells, pharmaceutical compositions and articles of manufacture. This invention further provides methods for determining whether a test compound interacts with an atpE protein, i.e. with the ATPase binding domain of the present invention, as well as pharmaceuticals compositions comprising said test compound, in particular as antimicrobials, more particular as antimycobacterial agent, even more particular for treating tuberculosis in a subject.