Mg2+-importing ATPase explained

magnesium-importing ATPase
Ec Number:	3.6.3.2
Go Code:	0015444

In enzymology, a Mg²⁺-importing ATPase is an enzyme that catalyzes the chemical reaction

ATP + H₂O + Mg₂+out

\rightleftharpoons ADP + phosphate + Mg₂+in

The 3 substrates of this enzyme are ATP, H₂O, and Mg²⁺, whereas its 3 products are ADP, phosphate, and Mg²⁺.

This enzyme belongs to the family of hydrolases, specifically those acting on acid anhydrides to catalyse transmembrane movement of substances. The systematic name of this enzyme class is ATP phosphohydrolase (Mg²⁺-importing).

The mgtA gene which encodes this enzyme is thought to be regulated by a magnesium responsive RNA element.^[1] A human enzyme was found in erythrocytes^[2] but the observation could not be confirmed.

References

• Tao T, Snavely MD, Farr SG, Maguire ME . 1995 . Magnesium transport in Salmonella typhimurium: mgtA encodes a P-type ATPase and is regulated by Mg2+ in a manner similar to that of the mgtB P-type ATPase . J. Bacteriol. . 177 . 2654 - 62 . 7751273 . 10 . 176934 . 10.1128/jb.177.10.2654-2662.1995.

• Kaczmarek MT, Maguire ME . 1998 . The CorA Mg2+ transport protein of Salmonella typhimurium Mutagenesis of conserved residues in the third membrane domain identifies a Mg2+ pore . J. Biol. Chem. . 273 . 28663 - 9 . 9786860 . 10.1074/jbc.273.44.28663 . 44 . free .

Notes and References

1. Groisman EA, Cromie MJ, Shi Y, Latifi T . A Mg2+-responding RNA that controls the expression of a Mg2+ transporter. . Cold Spring Harb Symp Quant Biol . 71 . 251–8 . 2006 . 17381304 . 10.1101/sqb.2006.71.005. free .
2. Szemraj J, Sobolewska B, Gulczynska E, Wilczynski J, Zylinska L . Magnesium sulfate effect on erythrocyte membranes of asphyxiated newborns . Clin. Biochem. . 38 . 5 . 457–64 . May 2005 . 15820777 . 10.1016/j.clinbiochem.2005.02.005 .