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.
Bibliographical noteFunding Information:
This work was supported by Grants from the National Science Foundation (MCB-0112826 and -0516690) to NEO and by the US Department of Energy (DE-FG02-02ER15353) to NEO and LMH and grants BIO2004-02687 from Spanish MEC and SP22-CT-2004 from European Union to J.A.G.
- Arabidopsis thaliana
- Capsid protein
- O-GlcNAc transferase
- Plum pox virus
- SECRET AGENT