To allow the muscle cell to contract, tropomyosin must be moved to uncover the binding sites on the actin.
32.
X-ray diffraction and cryoelectron microscopy suggest that tropomyosin sterically blocks the access of myosin to the actin filament.
33.
The systematic name of this enzyme class is "'ATP : tropomyosin O-phosphotransferase " '.
34.
These observations have been supported by studies on different tropomyosin isoforms, showing how tropomyosin populations were relocated during neuron maturation.
35.
These observations have been supported by studies on different tropomyosin isoforms, showing how tropomyosin populations were relocated during neuron maturation.
36.
However, the over-expression of Tropomyosin Br3 had the opposite effect, decreasing myosin activity in the same region.
37.
Within this type of muscle, caldesmon and calmodulin control the tropomyosin-mediated transition between on and off activity states.
38.
Caldesmon binds to actin, tropomyosin, calmodulin, and myosin, of which its interactions with actin are most important.
39.
For example, smooth muscle and skeletal muscle express alternate isoforms distinguished by mutually exclusive exon selection in alpha-tropomyosin.
40.
The L203 truncation deletes the binding sites for TnI and TnC but preserves both tropomyosin-binding sites 1 and 2.
