Cloning, expression and purification of cytochrome c 6 from the brown alga Hizikia fusiformis and complete X-ray diffraction analysis of the structure

• Published in: Acta crystallographica. Section F, Structural biology and crystallization communications Structural biology and crystallization communications, 2008-08, Vol.64 (8), p.674-680
• Main Authors: Akazaki, Hideharu, Kawai, Fumihiro, Chida, Hirotaka, Matsumoto, Yuichirou, Hirayama, Mao, Hoshikawa, Ken, Unzai, Satoru, Hakamata, Wataru, Nishio, Toshiyuki, Park, Sam-Yong, Oku, Tadatake
• Format: Article
• Language: English
• Subjects: Protein Structure Communications
• ISSN: 1744-3091; 1744-3091
• DOI: 10.1107/S1744309108017752

The crystal structure of cytochrome c 6 from the brown alga H. fusiformis has been determined at 1.6 Å resolution. The amino-acid sequence and tertiary structure of H. fusiformis cytochrome c 6 were very similar to those of red algal cytochrome c 6 rather than those of green algal cytochrome c 6 . The primary sequence of cytochrome c 6 from the brown alga Hizikia fusiformis has been determined by cDNA cloning and the crystal structure has been solved at 1.6 Å resolution. The crystal belonged to the tetragonal space group P 4 1 2 1 2, with unit-cell parameters a = b = 84.58, c = 232.91 Å and six molecules per asymmetric unit. The genome code, amino-acid sequence and crystal structure of H. fusiformis cytochrome c 6 were most similar to those of red algal cytochrome c 6 . These results support the hypothesis that brown algae acquired their chloroplasts via secondary endosymbiosis involving a red algal endo­symbiont and a eukaryote host.