Sumoylation sites in UL44 as identified by mass spectrometry.

Tryptic peptides derived from UL44 conjugated to SUMO-1. The table lists the measured m/z values, the experimentally determined (Exp.) molecular weights (M.W.) in Da, the calculated (Cal.) M.W. in Da as determined by database search, and the mass difference between calculated and experimental M.W. in Da. The amino acid sequences are listed with their positions within UL44 protein. Underlined bold amino acid indicates the SUMO-1-conjugated lysine in UL44, that is also listed in the far right column. Amino acids are in one-letter code. Asterisks indicate that the specific sumoylation site was predicted with the SUMOplot software.