FIG 1.

UL16 and the deletion mutants used in this study. The N- and C-terminal domains of UL16 are shown, and mutants expressing each of these are referred to by “NT” and “CT” names. The first 40, nonconserved residues are dispensable for binding to UL11, gE, and VP22. Positions and residue numbers of the 20 cysteines of UL16 are indicated. The eight conserved cysteines reside in the regulatory CTD and are shown in bold. The five nonconserved cysteines in the NTD were replaced with serines to generate the NT(5C−) mutant. The first 10 amino acids of the Src oncoprotein, which act as a membrane-targeting sequence (shown as a wavy line), were added to the N-terminal ends of NT and CT to generate sCT and sNT. Asterisks indicate the three cysteines that each activate binding of full-length UL16 to UL11 when changed to serine. Two subregions of the CTD that are sufficient for mitochondrial targeting (Mito 1 and Mito 2) are shaded.