The ATPase activity of molecular chaperones appears to depend on the s
tructure of determinants of the recognized protein target. The role of
chaperones in protein folding and organization of protomers in oligom
eric protein complexes is discussed The regulatory role of the conditi
onal ATPase activity of chaperones and other regulatory proteins is an
alyzed. It is proposed that conditional ATPases increase the specifici
ty of interaction of macromolecules.