Uptake of iron from ferric-citrate in the cyanobacteria Synechocystis PCC6803.
Iron is an essential element for bacterial growth. Its intracellular concentration is mainly controlled at the uptake level, which is mediated by iron-dicitrate transport in various prokaryotes. We report here that the cyanobacterium Synechocystis PCC6803 takes up iron from ferric citrate. This process is dependent of the iron:citrate ratio, with a better efficiency for the highest concentration of citrate. The iron-citrate complex is the substrate of this active uptake, inhibited in part by the uncoupler FCCP. Iron starvation activates this uptake. These data suggest the existence of a specific ferric citrate receptor on the cyanobacterial membrane.
Laboratoire de Biologie Moléculaire Végétale, CNRS-Université Joseph Fourier, Grenoble, France.
A M
AM
Labouré
J F
JF
Briat
D001693:Biological Transport, Active; D002951:Citrates / Q000493:pharmacokinetics*; D000458:Cyanobacteria / Q000254:growth & development / Q000378:metabolism*; D005290:Ferric Compounds / Q000493:pharmacokinetics*; D007501:Iron / Q000493:pharmacokinetics*
D002951:Citrates; D005290:Ferric Compounds; D007501:Iron