Scott Cheryl L, Hartweck Lynn M, de Jesús Pérez José, Chen Dinghu, García Juan Antonio, Olszewski Neil E
Department of Plant Biology, University of Minnesota, 1445 Gortner Avenue, 250 Biological Sciences Center, St. Paul, MN 55108, USA.
FEBS Lett. 2006 Oct 30;580(25):5829-35. doi: 10.1016/j.febslet.2006.09.046. Epub 2006 Sep 29.
The capsid protein of Plum pox virus (PPV-CP) is modified with O-linked GlcNAc (O-GlcNAc). While Arabidopsis has two O-GlcNAc transferases, SECRET AGENT (SEC) and SPINDLY (SPY), previous work suggests that SEC modifies PPV-CP and that the modification plays a role in the infection process. Here, we show that when co-expressed in Escherichia coli SEC modifies PPV-CP. Deletion mapping and site-directed mutagenesis identified three threonine and a serine located near the N-terminus of PPV-CP that are modified by SEC. Two of these threonines have recently been shown to be modified in virus from plants suggesting that SEC has the same specificity in plants and E. coli.
李痘病毒（PPV）的衣壳蛋白（PPV-CP）被O-连接的N-乙酰葡糖胺（O-GlcNAc）修饰。拟南芥有两种O-GlcNAc转移酶，即“特工”（SEC）和“细长”（SPY），先前的研究表明SEC修饰PPV-CP，且这种修饰在感染过程中起作用。在此，我们表明，当在大肠杆菌中共同表达时，SEC修饰PPV-CP。缺失定位和定点诱变确定了PPV-CP N端附近被SEC修饰的三个苏氨酸和一个丝氨酸。最近已证明这些苏氨酸中的两个在来自植物的病毒中被修饰，这表明SEC在植物和大肠杆菌中具有相同的特异性。
