Chlorophyll a oxygenase ( CAO ) is involved in chlorophyll b formation from chlorophyll a

作者：Ayumi Tanaka, Hisashi Itô, Ryouichi Tanaka, Nobuaki Tanaka, Kazuichi Yoshida, Kiyotaka Okada · 发表于：Proceedings of the National Academy of Sciences · 年份：1998 · DOI：10.1073/pnas.95.21.12719 · 被引用次数：459 · 研究领域：Photosynthetic Processes and Mechanisms、Genomics and Phylogenetic Studies、Microbial Community Ecology and Physiology

Chlorophyll b is an ubiquitous accessory pigment in land plants, green algae, and prochlorophytes. Its biosynthesis plays a key role in the adaptation to various light environments. We isolated six chlorophyll b-less mutants by insertional mutagenesis by using the nitrate reductase or argininosuccinate lyase genes as tags and examined the rearrangement of mutant genomes. We found that an overlapping region of a nuclear genome was deleted in all mutants and that this encodes a protein whose sequence is similar to those of methyl monooxygenases. This coding sequence also contains putative binding domains for a [2Fe-2S] Rieske center and for a mononuclear iron. The results demonstrate that a chlorophyll a oxygenase is involved in chlorophyll b formation. The reaction mechanism of chlorophyll b formation is discussed.