Dyneins are multisubunit, high molecular weight ATPases that interact with microtubules to generate force by converting the chemical energy of ATP into the mechanical energy of movement. Cytoplasmic or axonemal Dynein heavy, intermediate, light and light-intermediate chains are all components of minus end-directed motors; the complex transports cellular cargos towards the central region of the cell. Axonemal dynein motors contain one to three non-identical heavy chains and cause a sliding of microtubules in the axonemes of cilia and flagella in a mechanism necessary for cilia to beat and propel the cell. DNAH9 (Dynein, axonemal, heavy chain 9), also known as DYH9, HL20, DNEL1, Dnahc9 or DNAH17L, is a member of the Dynein heavy chain family and comprises one of the heavy chain subunits of axonemal Dynein. DNAH9 consists of an N-terminal stem which is responsible for interacting with other Dynein components and binding cargo, and four P-loops that comprise the motor domain at its C-terminus.