作　　者： ; ; ; ; ;

机构地区： 深圳大学生命科学学院深圳市微生物基因工程重点实验室

出　　处： 《水生生物学报》 2007年第5期666-670,共5页

摘　　要： 利用RT-PCR技术,从雨生红球藻(Haematococcus pluvialis 34-1n)总RNA中扩增出β-胡萝卜素羟化酶基因cDNA序列,将此序列亚克隆于pMD 18-T simple Vector上,经过序列测定,表明该基因的开放阅读框为879bp,编码292个氨基酸,与雨生红球藻(H. pluvialis Flotow NIES-144)β-胡萝卜素羟化酶基因氨基酸序列相比,其在编码氨基酸的第33位有一个氨基酸的缺失。在15、314、9和56位上的氨基酸也存在差异。多序列比对分析表明,雨生红球藻与莱茵衣藻的亲缘关系较近,与其他高等植物以及细菌的亲缘关系相对较远。 Astaxanthin （3,3＇-dihydroxy-β, β-carotene-4, 4＇-dione）, belonging to carotenoids, has been shown a series of biologiacal functions including an efficient antioxidant, enhancer of immune responses, an anti-cancer agent, and so on. β-carotene hydroxylase （CRTR-B） is one of the key enzymes involving in the natural astaxantin biosynthesis in H. pluvialis, crtR-B encod- ing β-carotene hydroxylase which is able to catalyse not only β-carotene to zeaxanthin but also canthaxanthin to astaxanthin. In this paper, crtR-B from H. pluvialis 34-1n was isolated and differences of crtR-B were observed between H. pluvialis 34-1n and H. pluvialis Flotow NIES-144. A pair of primers were designed according to β-carotene hydroxylase（GI：5852869）cDNA sequence in Genbank. Total RNA of H. pluvialis 34-1n was extracted and was transcribed. A cDNA fragment of β-carotene hydroxylase gene was amplified by using cDNA as templet and was further inserted into pMD 18-T simple Vector. The pMD 18-T simple Vector which contained the cDNA fragment was transformated into E. coli JMI09 for sequencing. The sequence analysis revealed that the cDNA fragment contained an opening frame of 879bp encoding 292 amino acids. An amino acid absence was found at the region of 33 compared with the published β-carotene hydroxylase gene and 4 amino acids differences were observed between the cloned gene and the sequence of H. pluvialis Flotow NIES-144. Multiple sequence alignment analysis indicated that the percentage identity of amino acid sequences ranged from 35.3% to 98.6% . There were only limited predicted amino acids sequence homologies to β-carotene hydroxylase in Alcaligenes sp and Erwinia uredovora. A higher amino acids homology was shown to the higher plants （40.6%--44.2%）. The most significant homology was found between H. pluvialis 34-1n and C. reinhardtii （49.0%）. The identity of crtR-B from H. pluvialis 34-1n to H. pluvialis Flotow NIES-144 was 98.6%.

关 键 词： 雨生红球藻 胡萝卜素羟化酶 虾青素

领　　域： [生物学]