摘 要：本研究以雨生红球藻（Haematococcus pluvialis）为研究对象，利用同源克隆和cDNA末端快速扩增技术（RACE）相结合的方法获得了雨生红球藻己糖激酶（HaeHK）基因的cDNA全长序列，并进行了序列分析。结果表明，HaeHK的cDNA全长为2 047 bp，其中开放阅读框的长度为1 716 bp，编码571个氨基酸。该蛋白预测的等电点（pI）为6.49，理论分子量为60.61 kD。经在线BLAST同源比对分析发现，其与团藻（Volvox carteri）和莱茵衣藻（Chlamydomonas reinhardtii）来源HKs的相似性分别达到50%和46%。通过序列比对和结构域分析可知，HaeHK蛋白存在与高等植物来源HKs相似的结构域，且具有HK家族的显著特征。高级结构同源建模表明其具有典型的“蝴蝶”结构。系统进化分析显示，高等植物和真核绿藻（Chlorophyta）来源HKs可能来自共同的祖先。本文首次从雨生红球藻中获得编码HaeHK的基因序列，为雨生红球藻中HK的表达和功能研究奠定基础，同时为解析雨生红球藻己糖利用及代谢的分子机制提供线索。

Abstact: In this study, the full-length cDNA sequence of HK gene was cloned from Haematococcus pluvialis by the combined homologous cloning and rapid-amplification of cDNA ends (RACE) methods. The physical and chemical properties, structure, and evolution were analyzed by bioinformatics methods. The full-length cDNA of HaeHK was 2 047 bp, it contained an open reading frame of 1 716 bp and encoded a protein of 571 amino acids. The deduced protein had a calculated molecular mass of 60.61 kD with an estimated isoelectric point (pI) of 6.49. Homologous alignment analysis revealed that HaeHK had similarity with other HKs from different organisms, Volvox carteri (50%) and Chlamydomonas reinhardtii (46%). Conserved domains analysis showed that the typical domain of the HKs was highly conserved in the protein sequences of HaeHK, including a remarkable characteristic with a“butterfly” tertiary structure. Phylogenetic analysis of the HKs showed that HaeHK is highly similar to the HKs of high plants and Chlorophyta, which indicated that they were from a common origin. In this study, the gene sequence encoding HK in Haematococcus pluvialis was obtained for the first time, the above results laid the foundation for further study on gene expression and functional identification, which may provide clues for revealing utilization and metabolism molecular mechanism of hexose in Haematococcus pluvialis.