van der Oost J, Schut G, Kengen S W, Hagen W R, Thomm M, de Vos W M
Laboratory of Microbiology, Wageningen Agricultural University, Hesselink van Suchtelenweg 4, NL-6307 CT Wageningen, The Netherlands.
J Biol Chem. 1998 Oct 23;273(43):28149-54. doi: 10.1074/jbc.273.43.28149.
The fermentative conversion of glucose in anaerobic hyperthermophilic Archaea is a variant of the classical Embden-Meyerhof pathway found in Bacteria and Eukarya. A major difference of the archaeal glycolytic pathway concerns the conversion of glyceraldehyde-3-phosphate. In the hyperthermophilic archaeon Pyrococcus furiosus, this reaction is catalyzed by an unique enzyme, glyceraldehyde-3-phosphate ferredoxin oxidoreductase (GAPOR). Here, we report the isolation, characterization, and transcriptional analysis of the GAPOR-encoding gene. GAPOR is related to a family of ferredoxin-dependent tungsten enzymes in (hyper)thermophilic Archaea and, in addition, to a hypothetical protein in Escherichia coli. Electron paramagnetic resonance analysis of the purified P. furiosus GAPOR protein confirms the anticipated involvement of tungsten in catalysis. During glycolysis in P. furiosus, GAPOR gene expression is induced, whereas the activity of glyceraldehyde-3-phosphate dehydrogenase is repressed. It is discussed that this unprecedented unidirectional reaction couple in the pyrococcal glycolysis and gluconeogenesis gives rise to a novel site of glycolytic regulation that might be widespread among Archaea.
厌氧嗜热古菌中葡萄糖的发酵转化是细菌和真核生物中经典的糖酵解途径（Embden-Meyerhof pathway）的一种变体。古菌糖酵解途径的一个主要差异涉及3-磷酸甘油醛的转化。在嗜热古菌激烈火球菌（Pyrococcus furiosus）中，该反应由一种独特的酶——3-磷酸甘油醛铁氧化还原酶（GAPOR）催化。在此，我们报告了编码GAPOR基因的分离、表征及转录分析。GAPOR与（嗜）热古菌中一类依赖铁氧化还原蛋白的钨酶相关，此外，还与大肠杆菌中的一种假定蛋白相关。对纯化的激烈火球菌GAPOR蛋白进行的电子顺磁共振分析证实了钨在催化过程中的预期参与。在激烈火球菌的糖酵解过程中，GAPOR基因表达被诱导，而3-磷酸甘油醛脱氢酶的活性则受到抑制。讨论了这种在火球菌糖酵解和糖异生中前所未有的单向反应偶联产生了一个新的糖酵解调节位点，该位点可能在古菌中广泛存在。
