摘要
宏基因组存在大量基因无法注释,被称为"暗物质"。对暗物质所编码的蛋白结构和功能的认知,不但有助于对其功能的注释,也有助于这些资源更好地开发利用。本文通过将两个取自热液口附近的海洋微生物宏基因组未注释的蛋白与数据库已注释蛋白进行差异比较,并对其性状进行相关分析,结果发现两样本与常温嗜压菌蛋白质组性状类似,而与嗜热嗜压菌差异显著:谷氦酸、赖氦酸、酪氦酸含量较低,天冬酰胺、谷氦酰胺、苏氦酸、丝氦酸含量较高;另外Cvp-bias、ERK两参数同样存在明显差异。主成分分析结果表明,谷氦酸因子系数为-0.3,与PC1成负相关,相关系数0.908;谷氦酰胺、丝氦酸均为0.3,与PC1成正相关,相关系数分别为0.914、0.955,说明PC1主要体现的是温度特征,PC2则存在复合因素的影响,在温度相当的情况下能反映压力的差异。据此可推测两个样品中已经注释的蛋白质与常温嗜压蛋白性状更接近,而未注释的蛋白则与之存在差异,暗示其可能存在一些新的嗜极机制。
A large number of genes in the metagenome that cannot be annotated, which called ＂dark matters＂. Cognizing the structure and fimction of protein encoded by dark matter is not only helpful to the annotation of its function, but also to the development and utilization of these resources. In this paper, we compared the non-annotated proteins from two marine microbial metagenomes of the hydrothermal vents with annotated metagenomes existing in database and analyzed their properties, found that both of their attributes were similar to the mesophilic-piezophilic groups, but had significant differences with the thermophilic-piezophilic groups： the content of lysine, glutamic acid and tyrosine were significantly low, while asparagine, glutamine, threonine and serine were significantly high; Cvp-bias and ERK parameters also exist visible differences. Principal component analysis showed that the factor coefficient of glutamic acid is -0.3, which have a negative correlation with PC1 with the correlation coefficient of 0.908, glutamine and serine is 0.3, which both have positive correlations with PC1 with the correlation coefficient 0.914 and 0.955, respectively. All these indicate that PC1 mainly reflects the temperature characteristics, and as to PC2, only when the temperature is nearly the same that it can reflect the pressure dif- ference. In a word, the proteins annotated in the two samples were more close to mesophilic-piezophilic groups, while the non-annotated proteins were different and this may indicate that they should have some novel extremophic adaptation mechanisms.
出处
《计算机与应用化学》
CAS
2016年第12期1313-1318,共6页
Computers and Applied Chemistry
基金
国家自然科学基金项目(21376103)
海洋公益性行业专项经费项目(201505026)
华侨大学研究生科研创新能力培育计划资助项目
关键词
海洋微生物
宏基因组
暗物质
氨基酸组成
主成分分析
marine microbial
metagenome
dark matter
amino acids composition
principal component analysis
