Three-Dimensional Model of a Novel Photosynthetic Ferredoxin Protein from Gardenia jasminoides

摘要

Chloroplast ferredoxins (Fd) are small proteins containing an iron-sulfur cluster in photosynthetic organisms. Fd functions as transferring electrons from photosystem I (PSI) to NADP+ via ferredoxin: NADPH~+ reductase (FNR). Fd is also the low-potential electron donor to many metabolic and regulatory pathways of the chloroplast. It plays a dual role in primary and secondary metabolism. In this work, we aimed to isolate a gene of Fd from Gardenia jasminoides. A G. jasminoides fruit cDNA library was constructed, and the GjFd cDNA was isolated from the cDNA library by sequencing method. The GjFd cDNA contains a predicted 444 bp open reading frame that encodes 147 amino acids. A bioinformatics analysis indicated that GjFd has conserved four iron-binding sites and FNR binding residues. A three-dimensional dimmer model of GjFd was built, the structure is similar to Fds from maize and spinach. The results suggest that GjFd is a typical photosynthetic ferredoxin protein mainly responsible for linear photosynthetic electron transort pathway.