Identification and localization of the CupB protein involved in constitutive CO2 uptake in the cyanobacterium, Synechocystis sp. strain PCC 6803

Plant Cell Physiol. 2008 Jun;49(6):994-7. doi: 10.1093/pcp/pcn074. Epub 2008 May 7.


Antibody against cMyc cross-reacted strongly with the CupB protein tagged with His6-cMyc (HM) in thylakoid membrane of Synechocystis sp. strain PCC 6803 but only faintly with the cytoplasmic membrane fraction. The protein was not detected in the membranes of the DeltandhD4 and DeltandhF4 mutants in which CupB was tagged with HM. We concluded that a CupB complex containing NdhD4 and NdhF4 is largely, if not exclusively, confined to the thylakoid membrane. Both CupB and NdhH were detected in a fraction containing protein complexes of > 450 kDa, obtained after nickel column and gel filtration chromatography of the membranes solubilized with n-dodecyl-beta-maltoside.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Bacterial Proteins / metabolism*
  • Carbon Dioxide / metabolism*
  • Cell Membrane / metabolism
  • Gene Expression Regulation, Bacterial / physiology
  • Mutation
  • Synechocystis / metabolism*


  • Bacterial Proteins
  • Carbon Dioxide