Schwender J, Müller C, Zeidler J, Lichtenthaler H K
Botanisches Institut, Universität Karlsruhe, Germany.
FEBS Lett. 1999 Jul 16;455(1-2):140-4. doi: 10.1016/s0014-5793(99)00849-2.
Various plant isoprenoids are synthesized via the non-mevalonate pathway of isopentenyl diphosphate formation. In this pathway, 1-deoxy-D-xylulose 5-phosphate (DOXP), the first intermediate, is transformed to 2-C-methyl-D-erythritol 4-phosphate (MEP) by an enzyme which was recently cloned from Escherichia coli. In order to find a plant homologue of this 1-deoxy-D-xylulose 5-phosphate reductoisomerase (DXR) we cloned a cDNA fragment from Arabidopsis thaliana which has high homology to the E. coli DXR. By expression of this fragment in E. coli we could demonstrate that it encodes a protein which transforms DOXP to MEP. The antibiotic fosmidomycin specifically inhibits this DXR enzyme activity.
多种植物类异戊二烯是通过异戊烯基二磷酸形成的非甲羟戊酸途径合成的。在该途径中，第一个中间体1-脱氧-D-木酮糖-5-磷酸（DOXP）通过一种最近从大肠杆菌中克隆出来的酶转化为2-C-甲基-D-赤藓糖醇-4-磷酸（MEP）。为了找到这种1-脱氧-D-木酮糖-5-磷酸还原异构酶（DXR）的植物同源物，我们从拟南芥中克隆了一个与大肠杆菌DXR具有高度同源性的cDNA片段。通过在大肠杆菌中表达该片段，我们能够证明它编码一种将DOXP转化为MEP的蛋白质。抗生素磷霉素能特异性抑制这种DXR酶的活性。
