Fig. 2.

pUL99-interacting partners at 72 hpi. A, UL99GFP-interacting proteins were isolated by affinity purification, resolved by gel electrophoresis, and identified by sequential MS and MS/MS analyses. *, peptides corresponding to ubiquitin (UBQ) were detected between 50- and 75-kDa molecular mass markers, and therefore its exact location could not be determined. B, representative MALDI LTQ Orbitrap CID spectra of [M + H]⁺ ions of peptides corresponding to ubiquitin. Following CID, the generated fragment ions were detected at the linear trap level.