Division of Life Science, Korea Basic Science Institute, Daejeon 305-806, Republic of Korea.
Mol Cell Proteomics. 2012 Jun;11(6):M111.015420. doi: 10.1074/mcp.M111.015420. Epub 2012 Jan 9.
Thermococcus onnurineus NA1, a sulfur-reducing hyperthermophilic archaeon, is capable of H(2)-producing growth, considered to be hydrogenogenic carboxydotrophy. Utilization of formate as a sole energy source has been well studied in T. onnurineus NA1. However, whether formate can be used as its carbon source remains unknown. To obtain a global view of the metabolic characteristics of H(2)-producing growth, a quantitative proteome analysis of T. onnurineus NA1 grown on formate, CO, and starch was performed by combining one-dimensional SDS-PAGE with nano UPLC-MS(E). A total of 587 proteins corresponding to 29.7% of the encoding genes were identified, and the major metabolic pathways (especially energy metabolism) were characterized at the protein level. Expression of glycolytic enzymes was common but more highly induced in starch-grown cells. In contrast, enzymes involved in key steps of the gluconeogenesis and pentose phosphate pathways were strongly up-regulated in formate-grown cells, suggesting that formate could be utilized as a carbon source by T. onnurineus NA1. In accordance with the genomic analysis, comprehensive proteomic analysis also revealed a number of hydrogenase clusters apparently associated with formate metabolism. On the other hand, CODH and CO-induced hydrogenases belonging to the Hyg4-II cluster, as well as sulfhydrogenase-I and Mbx, were prominently expressed during CO culture. Our data suggest that CO can be utilized as a sole energy source for H(2) production via an electron transport mechanism and that CO(2) produced from catabolism or CO oxidation by CODH and CO-induced hydrogenases may subsequently be assimilated into the organic carbon. Overall, proteomic comparison of formate- and CO-grown cells with starch-grown cells revealed that a single carbon compound, such as formate and CO, can be utilized as an efficient substrate to provide cellular carbon and/or energy by T. onnurineus NA1.
产氢古菌 Thermococcus onnurineus NA1 是一种能够进行产氢生长的硫磺还原超嗜热古菌，被认为是产氢羧化作用。在 T. onnurineus NA1 中，已经对其利用甲酸盐作为唯一能源进行了充分的研究。然而，甲酸盐是否可以作为其碳源仍然未知。为了获得产氢生长代谢特征的全局视图，通过一维 SDS-PAGE 与纳升 UPLC-MS(E)结合，对以甲酸盐、CO 和淀粉为唯一能源生长的 T. onnurineus NA1 进行了定量蛋白质组分析。共鉴定到 587 种蛋白质，对应于编码基因的 29.7%，并在蛋白质水平上对主要代谢途径（特别是能量代谢）进行了特征描述。糖酵解酶的表达是普遍的，但在淀粉生长的细胞中诱导程度更高。相比之下，在甲酸盐生长的细胞中，参与糖异生和戊糖磷酸途径关键步骤的酶被强烈上调，这表明 T. onnurineus NA1 可以利用甲酸盐作为碳源。与基因组分析一致，全面的蛋白质组分析还揭示了许多与甲酸盐代谢明显相关的氢化酶簇。另一方面，CODH 和 Hyg4-II 簇诱导的氢化酶以及硫氢酶-I 和 Mbx 在 CO 培养过程中显著表达。我们的数据表明，CO 可以通过电子传递机制被用作产氢的唯一能源，并且 CODH 和 CO 诱导的氢化酶分解代谢或 CO 氧化产生的 CO2 可能随后被同化到有机碳中。总的来说，与淀粉生长的细胞相比，甲酸盐和 CO 生长的细胞的蛋白质组比较表明，一种单一的碳化合物，如甲酸盐和 CO，可以被 T. onnurineus NA1 用作有效的底物，为细胞提供碳和/或能量。
