PARENT SESSION
Posters P2C Carbon and nitrogen interactions. Abstracts (614-616)

Overexpression and characterization of ferredoxin contained in nif operon in Chlorobium tepidum. Toshinari Furusawa^*,1, Daisuke Seo², Hidehiro Sakurai³, Kazuhito Inoue^{1, 4}, ¹ Dept. Biol. Sci., Japan² Dept. Chem., Japan³ Dept. Biol., Japan⁴ Dept. Biol., Japan

ABSTRACT- Chlorobium tepidum can grow with N₂ as the sole nitrogen source. The whole genome sequence of C. tepidum contains seven putative Fd genes and Seo et. al. purified three Fds, each binding two [4Fe-4S] clusters. One of the Fd genes, called CT1541 Fd gene, has a sequence motif for binding of [2Fe-2S] cluster, and is located on the downstream of nif operon that encode the structural genes of nitrogenase. RT-PCR revealed that CT1541 Fd gene was expressed only under combined-nitrogen depleted conditions and included in nif operon. CT1541 Fd gene was overexpressed in Escherichia coli, and UV-visible absorption spectrum of the purified Fd was similar to those of Clostridium pasteurianum and Azotobacter vinelandii [2Fe-2S] Fds.

KEY WORDS: ferredoxin, electron transport, nitrogenase