Schematic diagram of the transport model for REEs uptake in M. Extorquens. In the case of M. Extorquens, alcohols in the periplasm can be oxidized to aldehydes by REEs-dependent XoxF-MDH/ExaF-EDH. The electrons produced by these reactions are transferred from these enzymes to their dedicated cytochrome XoxG. For further metabolism, the aldehydes produced should be transferred to the cytoplasm. The functions of XoxF proteins include enzymatic oxidation of methanol in the periplasm and involvement in the regulation of other genes, possibly through the sensing or transduction of extracellular signals (REEs and the presence of stress factors). The question mark “?” indicates that there is no definite conclusion or that the intracellular pathway is unknown. The plus sign “+” represents positive regulation, and the minus sign “-” represents negative regulation. Lut corresponds to the gene shown in Fig. 1A, based on the text description. Adapted and updated from [18, 35, 65, 85, 86].