The invention concerns an electrically rotatable shaft, and more particularly, an adjusting shaft (1) of a fully variable mechanical valve train of an internal combustion engine, said shaft comprising an adjusting cam (2). The rapid and exact rotation of the adjusting shaft (1) that is required for the fully variable valve train is achieved by the fact that the valve train comprises an actuator (3) that comprises an adjusting lever (4) connected rotationally fast to the adjusting shaft (1), and the free end of the adjusting lever is articulated through a forked lever (5) on a screw nut ((8) of a screw-and-nut drive (6) that is driven by an electromotor (7).