Graham David E, Xu Huimin, White Robert H
Department of Biochemistry, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061-0308, USA.
FEBS Lett. 2002 Apr 24;517(1-3):190-4. doi: 10.1016/s0014-5793(02)02619-4.
The hyperthermophilic archaeon Methanococcus jannaschii uses several non-canonical enzymes to catalyze conserved reactions in glycolysis and gluconeogenesis. A highly diverged gene from that organism has been proposed to function as a phosphoglycerate mutase. Like the canonical cofactor-independent phosphoglycerate mutase and other members of the binuclear metalloenzyme superfamily, this M. jannaschii protein has conserved nucleophilic serine and metal-binding residues. Yet the substrate-binding residues are not conserved. We show that the genes at M. jannaschii loci MJ0010 and MJ1612 encode thermostable enzymes with phosphoglycerate mutase activity. Phylogenetic analyses suggest that this gene family arose before the divergence of the archaeal lineage.
嗜热古菌詹氏甲烷球菌利用多种非经典酶来催化糖酵解和糖异生中的保守反应。有人提出该生物体中一个高度分化的基因具有磷酸甘油酸变位酶的功能。与典型的不依赖辅因子的磷酸甘油酸变位酶以及双核金属酶超家族的其他成员一样,这种詹氏甲烷球菌蛋白具有保守的亲核丝氨酸和金属结合残基。然而,底物结合残基并不保守。我们发现,詹氏甲烷球菌基因座MJ0010和MJ1612处的基因编码具有磷酸甘油酸变位酶活性的耐热酶。系统发育分析表明,这个基因家族在古菌谱系分化之前就已出现。