SEQUENCE OF THE GAMMA-SUBUNIT OF SPIRULINA-PLATENSIS - A NEW PRINCIPLE OF THIOL MODULATION OF F0F1 ATP SYNTHASE

Abstract

The gene encoding the gamma subunit of Spirulina platensis F0F1, the relative of the chloroplast F-1 subunit responsible for thiol activation, has been cloned and sequenced. As in other cyanobacteria, a specific couple of cysteines like those involved in thiol modulation of the chloroplast enzyme was not found. Instead, two cysteine residues were identified in the Spirulina subunit at positions unique amongst all so far sequenced gamma subunits. Involvement of these cysteines in the thiol-modulation of the Spirulina enzyme reported before (Hicks and Yocum (1986) Arch. Biochem. Biophys, 245, 230-237, and Lerma and Gomez-Lojero (1987) Photosynth. Res. 11, 265-277) would manifest a re-invention of a regulatory mechanism.