Mutations in a putative chloride efflux transporter gene suppress the chloride requirement of photosystem II in the cytochrome c550-deficient mutant.
The cytochrome c550-deficient mutant (psbV-disruptant) of Synechocystis requires a high concentration of Cl(-) in the culture medium to support photosynthetic oxygen evolution. From this disruptant, we isolated spontaneous suppressor mutants that are able to grow photoautotrophically in the absence of Cl(-). Three independent mutations were identified: one was a deletion in slr0753 and two were a transposition of related insertion sequences in the same slr0753. The deduced product of slr0753 belongs to a novel group of the superfamily of ion efflux pumps and ion transporters. These results suggest that Slr0753 exports Cl(-) or a related anion, which is essential for PSII oxygen evolution.
Kobayashi
Mari
M
Department of Life Sciences (Biology), The University of Tokyo, Komaba 3-8-1, Meguro, Tokyo, 153-8902 Japan. teru@iam.u-tokyo.ac.jp
Katoh
Hiroshi
H
Ikeuchi
Masahiko
M
D027321:Anion Transport Proteins / Q000235:genetics* / Q000502:physiology; D002478:Cells, Cultured; D002712:Chlorides / Q000378:metabolism / Q000502:physiology*; D003574:Cytochrome c Group / Q000235:genetics* / Q000502:physiology; D015964:Gene Expression Regulation, Bacterial / Q000502:physiology; D005798:Genes, Bacterial / Q000235:genetics* / Q000502:physiology; D009154:Mutation / Q000235:genetics; D010100:Oxygen / Q000378:metabolism; D045332:Photosystem II Protein Complex / Q000235:genetics / Q000502:physiology*; D046939:Synechocystis / Q000166:cytology / Q000235:genetics* / Q000378:metabolism
D027321:Anion Transport Proteins; D002712:Chlorides; D003574:Cytochrome c Group; D045332:Photosystem II Protein Complex; C031732:cytochrome C-550; D010100:Oxygen