Tao Luan, Yao Henry, Kasai Hiroaki, Misawa Norihiko, Cheng Qiong
Biological and Chemical Sciences and Engineering, Central Research and Development, E. I. DuPont. de Nemours Inc., Experimental Station, E328/B48, Wilmington, DE 19880-0328, USA.
Mol Genet Genomics. 2006 Jul;276(1):79-86. doi: 10.1007/s00438-006-0121-0. Epub 2006 Apr 20.
A carotenoid synthesis gene cluster was isolated from a marine bacterium Algoriphagus sp. strain KK10202C that synthesized flexixanthin. Seven genes were transcribed in the same direction, among which five of them were involved in carotenoid synthesis. This cluster had a unique gene organization, with an isoprenoid gene, ispH (previously named lytB), being present among the carotenoid synthesis genes. The lycopene beta-cyclase encoded by the crtY ( cd ) gene appeared to be a fusion of bacterial heterodimeric lycopene cyclase CrtY(c) and CrtY(d). This was the first time that a fusion-type of lycopene beta-cyclase was reported in eubacteria. Heterologous expression of the Algoriphagus crtY ( cd ) gene in lycopene-accumulating Escherichia coli produced bicyclic beta-carotene. A biosynthesis pathway for monocyclic flexixanthin was proposed in Algoriphagus sp. strain KK10202C, though several of the carotenoid synthesis genes not linked with the cluster have not yet been cloned.
从一株合成柔红霉素的海洋细菌Algoriphagus sp. 菌株KK10202C中分离出一个类胡萝卜素合成基因簇。七个基因同向转录，其中五个参与类胡萝卜素合成。该基因簇具有独特的基因组织，在类胡萝卜素合成基因中存在一个类异戊二烯基因ispH（以前称为lytB）。由crtY (cd) 基因编码的番茄红素β-环化酶似乎是细菌异二聚体番茄红素环化酶CrtY(c) 和CrtY(d) 的融合体。这是首次在真细菌中报道融合型番茄红素β-环化酶。Algoriphagus crtY (cd) 基因在积累番茄红素的大肠杆菌中的异源表达产生了双环β-胡萝卜素。尽管尚未克隆一些与该基因簇不相关的类胡萝卜素合成基因，但在Algoriphagus sp. 菌株KK10202C中提出了单环柔红霉素的生物合成途径。
