A carotenogenic gene cluster from Brevibacterium linens with novel lycopene cyclase genes involved in the synthesis of aromatic carotenoids
A carotenogenic gene cluster from Brevibacterium linens with novel lycopene cyclase genes involved in the synthesis of aromatic carotenoids
复制标题
DOI：
10.1007/s004380051186
复制
发表时间：
2000-04-01
期刊：
影响因子：
--
通讯作者：
Sandmann, G
中科院分区：
文献类型：
--
作者：
Krubasik, P;Sandmann, G
克隆并鉴定了具有重要商业价值的棒状细菌短杆菌（Brevibacterium linens）的致胡萝卜素基因簇。通过对一个无色黄芽孢杆菌突变体的功能互补，构建了亚麻芽孢杆菌基因表达文库，获得了一个crt簇的片段，筛选转化细胞产生黄色色素。随后对一个cosmid文库进行筛选，克隆出了亚麻属植物的整个crt簇。根据序列同源性鉴定了合成芳香类胡萝卜素异肾上腺素所需的所有基因。此外，一种新型的番茄红素环化酶是通过一个积累番茄红素的黄芽孢杆菌突变体的互补而鉴定出来的。两个名为crtYc和crtYd的基因分别编码125个和107个氨基酸的多肽，它们是将番茄红素转化为对胡萝卜素所必需的。这些多肽的氨基酸序列显示与任何已知的番茄红素环化酶没有相似性。这是类胡萝卜素生物合成转化的第一个例子，其中涉及两种不同的基因产物，可能形成异源二聚体。
The carotenogenic (at) gene cluster from Brevibacterium linens, a member of the commercially important group of coryneform bacteria, was cloned and identified. An expression library of B, linens genes was constructed and a fragment of the crt cluster was obtained by functional complementation of a colourless B. flavum mutant, screening transformed cells for production of a yellow pigment. Subsequent screening of a cosmid library resulted in the cloning of the whole crt cluster from B. linens. All genes necessary for the synthesis of the aromatic carotenoid isorenieratene were identified on the basis of sequence homologies. In addition a novel type of lycopene cyclase was identified by complementation of a lycopene-accumulating B. flavum mutant. Two genes, named crtYc and crtYd, which code for polypeptides of 125 and 107 amino acids, respectively, are necessary to convert lycopene to p-carotene. The amino acid sequences of these polypeptides show no similarity to any of the known lycopene cyclases. This is the first example of a carotenoid biosynthetic conversion in which two different gene products are involved, probably forming a heterodimer.