the genome characteristics and predicted function of methyl-group oxidation pathway in the obligate aceticlastic methanogens, methanosaeta spp基因组甲基氧化途径的特点和预测功能预留aceticlastic产甲烷菌,methanosaeta spp.pdf

The Genome Characteristics and Predicted Function of Methyl-Group Oxidation Pathway in the Obligate Aceticlastic Methanogens, Methanosaeta spp. 1,2 3 1 1 4 1 1 Jinxing Zhu , Huajun Zheng , Guomin Ai , Guishan Zhang , Di Liu , Xiaoli Liu , Xiuzhu Dong * 1 State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing, People’s Republic of China, 2 Graduate School, Chinese Academy of Sciences, Beijing, People’s Republic of China, 3 Shanghai-MOST Key Laboratory of Health and Disease Genomics, Chinese National Human Genome Center at Shanghai, Shanghai, People’s Republic of China, 4 Information center, Institute of Microbiology, Chinese Academy of Sciences, Beijing, People’s Republic of China Abstract In this work, we report the complete genome sequence of an obligate aceticlastic methanogen, Methanosaeta harundinacea 6Ac. Genome comparison indicated that the three cultured Methanosaeta spp., M. thermophila, M. concilii and M. harundinacea 6Ac, each carry an entire suite of genes encoding the proteins involved in the methyl-group oxidation pathway, a pathway whose function is not well documented in the obligately aceticlastic methanogens. Phylogenetic analysis showed that the methyl-group oxidation-involving proteins, Fwd, Mtd, Mch, and Mer from Methanosaeta strains cluster with the methylotrophic methanogens, and were not closely related to those from the hydrogenotrophic methanogens. Quantitative PCR detected the expression of all genes for this pathway, albeit ten times lower than the genes for aceticlastic methanogenesis in strain 6Ac. Western blots also revealed the expression of fwd and mch, genes involv