Department of Synthetic Chemistry and Biological Chemistry, Graduate School of Engineering, Kyoto University, Katsura, Nishikyo-ku, Kyoto 615-8510, Japan.
Curr Opin Microbiol. 2011 Jun;14(3):307-14. doi: 10.1016/j.mib.2011.04.014. Epub 2011 May 24.
The Archaea harbor many metabolic pathways that differ to previously recognized classical pathways. Glycolysis is carried out by modified versions of the Embden-Meyerhof and Entner-Doudoroff pathways. Thermophilic archaea have recently been found to harbor a bi-functional fructose-1,6-bisphosphate aldolase/phosphatase for gluconeogenesis. A number of novel pentose-degrading pathways have also been recently identified. In terms of anabolic metabolism, a pathway for acetate assimilation, the methylaspartate cycle, and two CO2-fixing pathways, the 3-hydroxypropionate/4-hydroxybutyrate cycle and the dicarboxylate/4-hydroxybutyrate cycle, have been elucidated. As for biosynthetic pathways, recent studies have clarified the enzymes responsible for several steps involved in the biosynthesis of inositol phospholipids, polyamine, coenzyme A, flavin adeninedinucleotide and heme. By examining the presence/absence of homologs of these enzymes on genome sequences, we have found that the majority of these enzymes and pathways are specific to the Archaea.
古菌拥有许多代谢途径，这些途径与先前公认的经典途径不同。糖酵解是通过经过修饰的 Embden-Meyerhof 和 Entner-Doudoroff 途径进行的。最近发现嗜热古菌拥有一种用于糖异生的双功能果糖-1,6-二磷酸醛缩酶/磷酸酶。最近还发现了一些新的戊糖降解途径。在合成代谢方面，已经阐明了用于乙酸盐同化、甲基天冬氨酸循环以及两条 CO2 固定途径（3-羟基丙酸/4-羟基丁酸循环和二羧酸/4-羟基丁酸循环）的途径。就生物合成途径而言，最近的研究阐明了参与肌醇磷脂、多胺、辅酶 A、黄素腺嘌呤二核苷酸和血红素生物合成的几个步骤的酶。通过检查这些酶在基因组序列上的同源物的存在/缺失，我们发现这些酶和途径大多数都是古菌所特有的。
