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Sequencing and modification of the gene encoding the 42-kilodalton protein in the cytoplasmic membrane of Synechococcus PCC 7942

Journal Article · · Plant Physiology; (USA)
DOI:https://doi.org/10.1104/pp.93.1.305· OSTI ID:5922176
;  [1]; ;  [2]
  1. Institute of Physical and Chemical Research, Saitama (Japan)
  2. E.I. Du Pont de Nemours Company, Wilmington, DE (USA)

A 42-kilodalton cytoplasmic membrane protein is synthesized when high CO{sub 2}-grown cells of Synechococcus PCC 7942 (Anacystis nidulans R2) are exposed to low CO{sub 2}. The structural gene for this protein (cmpA) has been cloned and sequenced and shown to encode a 450 amino acid polypeptide with a molecular mass of 49 kilodalton. A deletion mutant lacking the 42-kilodalton protein was obtained by transformation of Synechococcus PCC 7942 following in vitro mutagenesis of the cloned gene. There were no significant differences between the mutant and wild-type cells in their growth rates under either low or high CO{sub 2} conditions. The activity of inorganic carbon (C{sub i}) transport in the mutant was as high as that in the wild-type strain. In both types of cells, CO{sub 2} was the main species of C{sub i} transported and the activities of CO{sub 2} and HCO{sub 3}{sup {minus}} transport increased when high CO{sub 2}-grown cells were exposed to low CO{sub 2}. We conclude that the 42-kilodalton protein is not directly involved in the C{sub i}-accumulating mechanism of Synechococcus PCC 7942.

OSTI ID:
5922176
Journal Information:
Plant Physiology; (USA), Journal Name: Plant Physiology; (USA) Vol. 93:1; ISSN 0032-0889; ISSN PLPHA
Country of Publication:
United States
Language:
English