Sliding and ATPase.

Sliding machines composed of F-actin and myosin or microtubules and kinesin or dynein convert the free energy of ATP hydrolysis into sliding movements and mechanical work. Development of optical microscopy with micromanipulation techniques has made possible direct observation of single events of sliding exhibited by single sliding machines. The experimental data and theoretical consideration suggest that the influx-efflux coupling in these machines may be loose. Specific characters of sliding machines are summarized and the problems we have for understanding of the coupling mechanism are discussed.