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The properties of expressed product of chloroplast atpE gene

Shi Jin, Wei Jiamian, Shen Yungang

Shanghai Institute of Plant Physiology,The Chinese Academy of Sciences.Shanghai 200032

Abstract

The maize chloroplast atpE gene, which encodes the #epsilon# subunit of CF_(1), the coupling factor, was over-expressed in E. coli NM522 and then the expressed product was purified. The purified product was found to inhibit the ATPase activity of CF_(1) activated by heat or methanol. The antiserum raised against the expressed product, stimulated ATPast activity, and also decreased the quenching of 9-aminoacridine fluorescence. This result can be explained by the antiserum specific binding of the #epsilon# subunit from the CF_(1), which alleviated the function of #epsilon# subunit. The expressed product stimulated cyclic and non-cyclic photophosphorylation and its antiserum stimulated non-cyclic photophosphorylation but inhibited cyclic photophosphorylation, which can be explained by assuming that the two types of photophosphorylation utilize differently situated CF_(1) in thylakoids. Perhaps, ATP formation by non-cyclic photophosphorylation is only synthesized by CF_(1) of unappressed part of grana thylakoids, but that by cyclic photophosphorylation is pressed part of grana thylakoids but also CF_(1) of stroma thylakoids.

Key words: Chloroplast;AtpE gene;ε subunit;ATPase;Photophosphorylation

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Citing This Article：

Shi Jin, Wei Jiamian, Shen Yungang. The properties of expressed product of chloroplast atpE gene. Acta Physiol Sin 1996; 48 (3): (in Chinese with English abstract).