A possible regulatory role for the metal-binding domain of CadA, the Listeria monocytogenes Cd2+-ATPase.
Using the baculovirus/Sf9 expression system, we produced CadA and DeltaMBD, a metal-binding domain, truncated CadA. Both proteins had the expected properties of P-type ATPases: ATP-induced Cd2+ accumulation, Cd2+-sensitive ATP and Pi phosphorylation and ATPase activity. DeltaMBD displayed lower initial transport velocity as well as lower maximal ATPase activity than CadA. MBD truncation flattened the Cd2+ dependence of the ATPase activity and increased apparent Cd2+ affinity, suggesting a positive cooperativity between MBD and membranous transport sites. We propose that occupancy of MBD by Cd2+ modulates CadA activity.
Bal
N
N
Commissariat à l'Energie Atomique, Département de Biologie Moléculaire et Structurale, Laboratoire de Biophysique Moléculaire et Cellulaire, UMR CEA-CNRS-UJF 5090, 17 rue des Martyrs, 38054 Cedex 09, Grenoble, France.
Mintz
E
E
Guillain
F
F
Catty
P
P
D000251:Adenosine Triphosphatases / Q000737:chemistry / Q000378:metabolism*; D000818:Animals; D002384:Catalysis; D007700:Kinetics; D008089:Listeria monocytogenes / Q000201:enzymology*; D011994:Recombinant Proteins / Q000737:chemistry / Q000378:metabolism; D018411:Spodoptera
D011994:Recombinant Proteins; D000251:Adenosine Triphosphatases; C059771:cadmium translocating ATPase