ATPase enzyme needed for muscle contraction is located in -

The thick filaments of a myofibril are made of myosin. Each myosin molecule has a globular head (heavy meromyosin).
The myosin head has ATPase activity and binding sites for both ATP and actin.
It hydrolyses ATP to ADP and $P_i$, and uses the energy released to bind to actin, form a cross bridge and pull the thin filaments towards the centre of the sarcomere (sliding filament theory).
Actin, troponin and tropomyosin form the thin filaments and have no ATPase activity; actinin anchors actin at the Z line.
So the ATPase enzyme needed for muscle contraction is located in myosin.