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Evolution from photosynthetic bacteria to cyanobacteria based on carotenoids and carotenogenesis genes

基于类胡萝卜素和胡萝卜素生成基因的从光合细菌到蓝细菌的进化

基本信息

批准号：
16570038
负责人：
TAKAICHI Shinichi
金额：
$ 1.79万
依托单位：
Nippon Medical School
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
2004
资助国家：
日本
起止时间：
2004 至 2006
项目状态：
已结题

项目摘要

1. Carotenoids in a novel purple sulfur bacterium(2S)-Spirilloxanthin-2-ol, whose partial structure is similar to that of myxol and stereochemistry is the same with that of (2S)-myxol in cyanobacteria, was identified.2. p-Carotene ketolases in Anabaena sp. PCC 7120Two distinct p-Carotene ketolases, CrtO and CrtW, have been known. CrtO catalyzed β-carotene to echinenone, and CrtW catalyzed myxol to ketomyxol. Nostoc punctiforme have two CrtWs, and the substrate of one is β-carotene, while the other is myxol.3. Phytoene desaturase in Gloeobacter violaseusFor desaturation of phytoene to lycopene, cyanobacteria need three enzymes, CrtP, CrtQ and CrtH. Gloeobacter did not use these enzymes, but used bacterial-type, CrtI. This species is the first example to use CrtI in cyanobacteria.4. Carotenoids in some cyanobacteriaCarotenoids of 19 species including Anabaena, Nostoc and filamentous cyanobacteria, were identified. Glycoside moieties of myxol glycosides were not identified. They had unique ketocarotenoids and myxol glycosides. For carotenogenesis, lycopene cyclase, β-carotene hydroxylase (CrtR), β-carotene 2-hydroxylase (CrtG-like), β-carotene ketolases (CrtO, CrtW) and myxol synthesis enzymes might be included. Various carotenoid compositions may be owing to presence or absence of carotenogenesis gene(s) and/or the substrate specificity of the enzyme(s). These findings are very interesting on the evolution of carotenoids from photosynthetic bacteria to cyanobacteria.

1.鉴定了一种新的紫硫细菌（2S）-螺黄-2-醇中的类胡萝卜素，其部分结构与粘液醇相似，立体化学结构与蓝藻中的（2S）-粘液醇相同.鱼腥藻PCC 7120中的β-胡萝卜素酮醇酶已知有两种不同的β-胡萝卜素酮醇酶CrtO和CrtW。CrtO催化β-胡萝卜素生成海胆烯酮，CrtW催化粘液醇生成酮粘液醇。点状念珠藻具有两个CrtW，一个CrtW的底物是β-胡萝卜素，另一个CrtW的底物是粘液素.蓝细菌将八氢番茄红素脱饱和为番茄红素需要三种酶，CrtP、CrtQ和CrtH。Gloeplasty没有使用这些酶，但使用细菌型CrtI。该物种是第一个在蓝藻中使用CrtI的例子。部分蓝藻中的类胡萝卜素类胡萝卜素共鉴定出鱼腥藻、念珠藻、丝状蓝藻等19种蓝藻。未鉴别出粘液醇糖苷的糖苷部分。它们具有独特的酮类胡萝卜素和粘液醇糖苷。对于胡萝卜素生成，可以包括番茄红素环化酶、β-胡萝卜素羟化酶（CrtR）、β-胡萝卜素2-羟化酶（CrtG样）、β-胡萝卜素酮醇酶（CrtO、CrtW）和粘液醇合成酶。各种类胡萝卜素组合物可归因于存在或不存在胡萝卜素生成基因和/或酶的底物特异性。这些发现对于类胡萝卜素从光合细菌到蓝藻的进化具有重要意义。