Sequence analysis of cucumber cotyledon ribulosebisphosphate carboxylase/oxygenase activase cDNA.

The cDNA encoding ribulosebisphosphate carboxylase/oxygenase activase from cotyledons of dark-grown cucumber seedlings has been isolated and sequenced. The 2.0 kilobase pair cDNA encodes a polypeptide with 413 amino acid residues which shows 70% identity with the rubisco activase from green leaves of spinach. The full-length cDNA was used to prepare rubisco activase by in vitro transcription. Subsequent in vitro translation led to the formation of a 46 kDa protein which is the putative precursor of a 42 kDa plastid enzyme.