Hua Shao-feng, Li Shu-ben, Tan Hai-dong, Zhao Jia-zheng
State Key Laboratory for Oxo Synthesis and Selective Oxidation, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou 730000, China.
Wei Sheng Wu Xue Bao. 2007 Feb;47(1):150-5.
Soluble methane monooxygenase (MMO) from methanotrophs is a member of binuclear iron-containing multicomponent oxygenases, which can catalyze bioconversion of methane to methanol at ambient temperature and regulate methane recycle in nature. The research focused mainly on the sequence analysis of 16S rDNA and sMMO genes from Methylomonas sp. GYJ3. With the aid of the information from GenBank, the PCR primers and the sequence primers were designed, obtained a 5690bp of sMMO fragment and a 1280bp of 16S rDNA. Sequence comparison for MMOX with counterpart of other five strains showed that from 78% to 99% identity in protein level and from 71 % to 97% identity in gene level, in the separate comparison of six components, only orfY component had a lower identical. The multiple alignment of MMOX amino acid sequence with other four strains showed that there is a high conservation, especially in two Fe binding regions. 16S rDNA phylogenetic analysis demonstrated that Methylomonas sp. GYJ3 is relative with gamma proteobacteria. Phylogenetic analysis of MMOX amino acid sequence showed that Methylomonas sp. GYJ3 is closer to Methylomonas sp. KSW III of type I methanotrophs. It was concluded that Methylomonas sp. GYJ3 is belong to the genus of type I methanotroph Methylomonas, and the result was a direct evidence for the sMMO can be expressed in type I methanotrophs. The theoretical pI of hydroxylase was 6.28 and the theoretical MW of hydroxylase was 248874.41Da.
来自甲烷营养菌的可溶性甲烷单加氧酶（MMO）是含双核铁的多组分加氧酶家族成员，其能够在常温下催化甲烷生物转化为甲醇，并调节自然界中的甲烷循环利用。该研究主要聚焦于甲基单胞菌属菌株GYJ3的16S rDNA和可溶性甲烷单加氧酶（sMMO）基因的序列分析。借助GenBank中的信息，设计了PCR引物和测序引物，获得了一条5690bp的sMMO片段和一条1280bp的16S rDNA。MMOX与其他五株对应物的序列比较表明，蛋白质水平上的同一性为78%至99%，基因水平上的同一性为71%至97%，在六个组分的单独比较中，只有orfY组分的同一性较低。MMOX氨基酸序列与其他四株菌株的多重比对显示存在高度保守性，尤其是在两个铁结合区域。16S rDNA系统发育分析表明，甲基单胞菌属菌株GYJ3与γ-变形菌纲相关。MMOX氨基酸序列的系统发育分析表明，甲基单胞菌属菌株GYJ3与I型甲烷营养菌甲基单胞菌属菌株KSW III更为接近。得出结论，甲基单胞菌属菌株GYJ3属于I型甲烷营养菌甲基单胞菌属，该结果直接证明了可溶性甲烷单加氧酶可在I型甲烷营养菌中表达。羟化酶的理论pI为6.28，羟化酶的理论分子量为248874.41Da。
