Li Qingbo, Li Lingyun, Rejtar Tomas, Karger Barry L, Ferry James G
Center for Microbial Structural Biology, Department of Biochemistry and Molecular Biology, 205 South Frear Laboratory, Penn State University, University Park, Pennsylvania 16802, USA.
J Proteome Res. 2005 Jan-Feb;4(1):112-28. doi: 10.1021/pr049832c.
Methanosarcina acetivorans is representative of the genus that is distinguished from all other methane-producing genera by extensive metabolic diversity predicted from the large genome. In Part I of this study, two-dimensional gel electrophoresis and MALDI-TOF-TOF mass spectrometry was used to investigate the proteome of methanol- or acetate-grown M. acetivorans, with the goal of an initial characterization of the diversity of the proteins synthesized. A total of 412 proteins were identified, representing nearly 10% of the ORFs, with nearly 30% conserved hypothetical or hypothetical. Of the 412 proteins, 188 were found in both acetate- and methanol-grown cells, 122 were detected only in acetate-grown cells, and 102 only in methanol-grown cells. The results revealed the expression of a remarkable number of redundant genes which encode enzymes involved in the pathways for methanogenesis from methanol or acetate, suggesting an important role for the unusually high percentage of redundant genes in Methanosarcina species. Evidence was obtained for synthesis of a sodium-transporting oxidoreductase in acetate-grown cells, with the potential to function in energy conservation. Several transcriptional regulatory proteins were identified that also function in the Bacteria domain, raising questions regarding their interaction with the Archaea/Eucarya-type basal transcription apparatus. In addition, a significant number of proteins involved in protein folding were shown to be synthesized in methanol- and acetate-grown cells. These studies provide the first examination of the protein diversity of M. acetivorans.
嗜乙酸甲烷八叠球菌是该属的代表，它与所有其他产甲烷属的区别在于，从其庞大的基因组预测出具有广泛的代谢多样性。在本研究的第一部分，二维凝胶电泳和基质辅助激光解吸电离飞行时间串联质谱被用于研究以甲醇或乙酸盐为生长底物的嗜乙酸甲烷八叠球菌的蛋白质组，目的是初步表征所合成蛋白质的多样性。总共鉴定出412种蛋白质，占开放阅读框的近10%，其中近30%为保守假设蛋白或假设蛋白。在这412种蛋白质中，188种在以乙酸盐和甲醇为生长底物的细胞中均被发现，122种仅在以乙酸盐为生长底物的细胞中被检测到，102种仅在以甲醇为生长底物的细胞中被检测到。结果揭示了大量冗余基因的表达，这些基因编码参与甲醇或乙酸盐产甲烷途径的酶类，表明冗余基因在甲烷八叠球菌属中所占的异常高比例具有重要作用。有证据表明在以乙酸盐为生长底物的细胞中合成了一种钠转运氧化还原酶，它具有在能量守恒中发挥作用的潜力。鉴定出了几种在细菌域中也发挥作用的转录调节蛋白，这引发了关于它们与古菌/真核生物型基础转录装置相互作用方式的问题。此外，大量参与蛋白质折叠的蛋白质在以甲醇和乙酸盐为生长底物的细胞中均被显示会被合成。这些研究首次对嗜乙酸甲烷八叠球菌的蛋白质多样性进行了考察。
