First domain of the ATP-binding cassette component of cobalt transport system
Domain I of the ABC component of a cobalt transport family found in bacteria, archaea, and eukaryota. The transition metal cobalt is an essential component of many enzymes and must be transported into cells in appropriate amounts when needed. This ABC transport system of the CbiMNQO family is involved in cobalt transport in association with the cobalamin (vitamin B12) biosynthetic pathways. Most of cobalt (Cbi) transport systems possess a separate CbiN component, the cobalt-binding periplasmic protein, and they are encoded by the conserved gene cluster cbiMNQO. Both the CbiM and CbiQ proteins are integral cytoplasmic membrane proteins, and the CbiO protein has the linker peptide and the Walker A and B motifs commonly found in the ATPase components of the ABC-type transport systems.