Structure, function and evolution of the Archaeal class I fructose-1,6-bisphosphate aldolase
Structure, function and evolution of the Archaeal class I fructose-1,6-bisphosphate aldolase
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DOI：
10.1042/bst0320259
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发表时间：
2004-04-01
影响因子：
3.9
通讯作者：
Pohl, E
中科院分区：
文献类型：
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作者：
Lorentzen, E;Siebers, B;Pohl, E
1，6-二磷酸果糖缩醛酶(FBPA)催化3-磷酸乙二醛和磷酸二羟丙酮的可逆羟醛缩合反应生成1，6-二磷酸果糖。到目前为止，已经发现了两类FBPA，它们依赖于不同的反应机制，第一类主要在真核生物中发现，第11类主要在细菌中发现。直到最近，编码具有FBPA活性的蛋白质的基因才在古生代被发现。古生菌的FBPA与传统的FBPA类成员没有任何显著的总体序列同源性，这提出了一个有趣的问题，即它们是通过趋同进化独立进化的，还是从共同的祖先分化而来的。对两株嗜热古生菌ThermoProteus tenox和狂热杆菌的FBPA的生化特性分析表明，这两种酶均采用席夫碱机制，属于I类缩醛酶。来自Tenox的古菌FBPA的晶体结构表明，与经典的FBPA I和11一样，蛋白质折叠是平行的(βα)(8)桶。底物结合的晶体结构允许详细的活性部位比较，这表明古生菌和经典的FBPA I之间存在六个重要的催化和底物结合残基，这进一步证明了这两个蛋白质序列家族有着共同的进化起源。此外，结构和序列分析表明，I类FBPA与(βα)(8)桶折叠的其他几个酶超家族具有共同的进化起源。
FBPA (fructose-1,6-bisphosphate aldolase) catalyses the reversible aldol condensation of glycefaldehyde 3-phosphate and dihydroxyacetone phosphate to form fructose 1,6-bisphosphate. Two classes of FBPA, which rely on different reaction mechanisms, have so far been discovered, class I mainly found in Eucarya and class 11 mainly in Bacteria. Only recently were genes encoding proteins with FBPA activity identified in Archaea. Archaeal FBPAs do not share any significant overall sequence identity with members of the traditional classes of FBPAs, raising the interesting question of whether they have evolved independently by convergent evolution or diverged from a common ancestor. Biochemical characterization of FBPAs of the two hyperthermophilic Archaea Thermoproteus tenox and Pyrococcus furiosus showed that the enzymes use a Schiff-base mechanism and thus belong to the class I aldolases. The crystal structure of the archaeal FBPA from T. tenox revealed that the protein fold, as for the classical FBPA I and 11, is that of a parallel (betaalpha)(8) barrel. A substrate-bound crystal structure allowed detailed active-site comparisons which showed the conservation of six important catalytic and substrate-binding residues between the archaeal and the classical FBPA I. This observation provides further evidence that the two sequence families of proteins share a common evolutionary origin. Furthermore, structure and sequence analysis indicate that the class I FBPA shares a common evolutionary origin with several other enzyme superfamilies of the (betaalpha)(8) barrel fold.