| 초록 |
The hyperthermophilc archaeon Thermoplasma acidophilum is known to have modified version of ED (Entner-Doudoroff) pathway. A key enzymes of this pathway, KDG (KDPG) aldolase, catalyzes the cleavage of KDG (KDPG) to glyceraldehyde (glyceraldehyde-3-phosphate) and pyruvate, and the subsequent conversion of glyceraldehyde (glyceraldehyde-3-phosphate) to glycerate (glycerate-3-phoshate) by glyceraldehydes dehydrogenase. In our previous studies, we identified and characterized glyceraldehyde dehydrogenase, and it was suggested that modifiedED pathway of T. acidophilum is a non-phosphorylative variant of the classic pathway. In this study, three hypothetical T. acidophilum aldolase genes (TA0619, TA0745, TA1157) were cloned and expressed in E.coli BL21 (DE3) CodonPlus strain. The substrate specificities of three aldolases were evaluated in the synthetic direction with a range of aldehyde substrates. This revealed non-phosphorylative ED pathway in T. acidophilum is another example of the versatility and flexibility of extremophile metabolic pathways. |
