Abstract: The petHL of Synechnococcus sp. PCC 7002 encoding FNR domain (FNRD) of FNR was amplified by PCR, and cloned into expressing vector pET-3a. Ovemxpression of petHL was achieved with E. coli BL21 (DE3). The recombinant FNRD was purified to homogeneity by DEAE-Sephadex A-50 and Sephadex G-100 chromatography. N-terminal amino acid sequencing showed that rFNRD was encoded by petHL and initial Met was not posttranslationally removed, rFNRD had the same absorption spectrum, optimal pH and optimal temperature as those of rFNR. rFNRD could catalyze photosynthetic electron transport from PT00 to NADP+ in vitro.

Key words: Cyanobacteria, FNR domain, Overexpression, Electron transport