Elucidation of a carotenoid biosynthesis gene cluster encoding a novel enzyme, 2,2′-β-hydroxylase, from Brevundimonas sp strain SD212 and combinatorial biosynthesis of new or rare xanthophylls
Elucidation of a carotenoid biosynthesis gene cluster encoding a novel enzyme, 2,2′-β-hydroxylase, from Brevundimonas sp strain SD212 and combinatorial biosynthesis of new or rare xanthophylls
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DOI：
10.1128/aem.71.8.4286-4296.2005
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发表时间：
2005-08-01
影响因子：
4.4
通讯作者：
Misawa, N
中科院分区：
文献类型：
--
作者：
Nishida, Y;Adachi, K;Misawa, N
以crtI序列为探针DNA，从海洋细菌Brevundimonas sp.菌株SD 212中分离到一个介导2-羟基虾青素合成的类胡萝卜素生物合成基因簇。序列分析显示该簇包含12个开放阅读框（ORF），包括7个已知基因crtW、crtY、crtI、crtB、crtE、idi和crtZ。通过使用大肠杆菌的互补研究对各个ORF进行功能分析，所述大肠杆菌由于其他细菌crt基因的存在而积累各种类胡萝卜素前体。除了在功能上鉴定已知的crt基因外，我们还发现一个（ORF 11，命名为crtG）编码一种新的酶，类胡萝卜素2，2 '-β-羟化酶，它与动物甾醇-C5-去饱和酶具有有趣的部分同源性。将crtG基因导入E. coli中积累玉米黄质和玉米黄质，所得转化体产生它们的2-羟基化和2，2 '-二羟基化产物，如通过它们的核磁共振和高效液相色谱/光电二极管阵列检测器/大气压化学电离质谱光谱数据所确定的，这些产物是结构新颖或稀有的叶黄素。新产生的类胡萝卜素对脂质过氧化有很强的抑制作用。
A carotenoid biosynthesis gene cluster mediating the production of 2-hydroxyastaxanthin was isolated from the marine bacterium Brevundimonas sp. strain SD212 by using a common crtI sequence as the probe DNA. A sequence analysis revealed this cluster to contain 12 open reading frames (ORFs), including the 7 known genes, crtW, crtY, crtI, crtB, crtE, idi, and crtZ. The individual ORFs were functionally analyzed by complementation studies using Escherichia coli that accumulated various carotenoid precursors due to the presence of other bacterial crt genes. In addition to functionally identifying the known crt genes, we found that one (ORF11, named crtG) coded for a novel enzyme, carotenoid 2,2'-beta-hydroxylase, which showed intriguingly partial homology with animal sterol-C5-desaturase. When this crtG gene was introduced into E. coli accumulating zeaxanthin and canthaxanthin, the resulting transformants produced their 2-hydroxylated and 2,2'-dihydroxylated products which were structurally novel or rare xanthophylls, as determined by their nuclear magnetic resonance and high-performance liquid chromatography/photodiode array detector/atmospheric pressure chemical ionization mass spectrometry spectral data. The new carotenoid produced was suggested to have a strong inhibitory effect on lipid peroxidation.