magnesium transporting ATPase (MgtA), similar to Escherichia coli MgtA and Salmonella typhimurium MgtA
MgtA is a membrane protein which actively transports Mg(2+) into the cytosol with its electro-chemical gradient rather than against the gradient as other cation transporters do. It may act both as a transporter and as a sensor for Mg(2+). In Salmonella typhimurium and Escherichia coli, the two-component system PhoQ/PhoP regulates the transcription of the mgtA gene by sensing Mg(2+) concentrations in the periplasm. MgtA is activated by cardiolipin and it highly sensitive to free magnesium in vitro. It consists of a transmembrane domain and three cytosolic domains: nucleotide-binding domain, phosphorylation domain and actuator domain, and belongs to the P-type ATPase type III subfamily. The P-type ATPases, are a large family of integral membrane transporters that are of critical importance in all kingdoms of life. They generate and maintain (electro-) chemical gradients across cellular membranes, by translocating cations, heavy metals and lipids, and are distinguished from other main classes of transport ATPases (F- , V- , and ABC- type) by the formation of a phosphorylated (P-) intermediate state in the catalytic cycle.
Jiyao W et al.(2023). "The conserved domain database in 2023.",