Review

Life implies motion. In cells, protein-based active molecular machines drive cell locomotion and intracellular transport, control cell shape, segregate genetic material, and split a cell in two parts. Key players among molecular machines driving these various cell functions are the cytoskeleton and motor proteins that convert chemical bound energy into mechanical work. Findings over the last decades in the field of in vitro reconstitutions of cytoskeletal and motor proteins have elucidated mechanistic details of these active protein systems. For example, a complex spatial and temporal interplay between the cytoskeleton and motor proteins is responsible for the translation of chemically bound energy into (directed) movement and force generation, which eventually governs the emergence of complex cellular functions. Understanding these mechanisms and the design principles of the cytoskeleton and motor proteins builds the basis for mimicking fundamental life processes. Here, a brief overview of actin, prokaryotic actin analogs, and motor proteins and their potential role in the design of a minimal cell from the bottom-up is provided