Cytoskeletal protein that is involved in cell-shape control through regulation of the length of the long axis. Forms helical filaments along the long axis of the cell. The helix-turn-helix (HTH) motif in the cytoplasmic domain of the N-terminus is involved in the formation of spirals to maintain the rigid rod shape. As this protein is anchored in the cytoplasmic membrane, the HTH motif may contribute to protein-protein interactions to form the RodZ helix, which is localized beneath the cytoplasmic membrane. The C-terminal domain may be critical for determination of the rod shape by probably interacting with enzymes required for synthesis of the peptidoglycan layer, including PBPs in the periplasm. Affects the lengths of both the long and short axes of the cell, but especially the long axis. Cells become shorter and fatter and form round or oval shapes. Belongs to the RodZ family.