Sadre Radin, Gruber Jens, Frentzen Margrit
RWTH Aachen University, Institute for Biology I, Botany, Worringerweg 1, 52056 Aachen, Germany.
FEBS Lett. 2006 Oct 2;580(22):5357-62. doi: 10.1016/j.febslet.2006.09.002. Epub 2006 Sep 12.
A cDNA of Chlamydomonas reinhardtii encoding a plastidial homogentisate prenyltransferase was identified. Functional expression studies in Escherichia coli revealed that the enzyme possessed properties similar to the prenyltransferase of Arabidopsis thaliana encoded by At3g11950 but different from the phytyltransferases of A. thaliana and Synechocystis. Unlike the phytyltransferases, the C. reinhardtii and the respective A. thaliana enzyme showed highest activities with solanesyl diphosphate, but were hardly active with phytyl diphosphate. Hence, these data provide evidence that the latter represent homogentisate solanesyltransferases involved in plastoquinone-9 biosynthesis. Overexpression of At3g11950 in A. thaliana, however, suggests that the solanesyltransferase can affect tocopherol biosynthesis as well.
鉴定出莱茵衣藻中一个编码质体尿黑酸异戊烯基转移酶的cDNA。在大肠杆菌中的功能表达研究表明，该酶具有与拟南芥At3g11950编码的异戊烯基转移酶相似的性质，但与拟南芥和集胞藻的植基转移酶不同。与植基转移酶不同，莱茵衣藻和相应的拟南芥酶对茄尼基二磷酸表现出最高活性，但对植基二磷酸几乎没有活性。因此，这些数据证明后者代表参与质体醌-9生物合成的尿黑酸茄尼基转移酶。然而，At3g11950在拟南芥中的过表达表明，茄尼基转移酶也可以影响生育酚的生物合成。
