Illustration of the motor domain of human dynein-1 in its inhibited state, which is known as the phi-particle. In this conformation two motor proteins are locked together. Dynein-1 is found in the cytoplasm of cells where it transports various cellular cargos along microtubules, a component of the cytoskeleton. Dyneins move towards the minus-end of the microtubule, which is usually orientated towards the cell's centre