TABLE 2.

Role of the putative TLM in the HBV pre-S2 in HDV assembly and infectivity^a

Protein or motif	Sequence	HDV assembly (107 GE/ml)	HDV MOI (GE/cell)	HDV infectivity (GE/cell)	HDV specific infectivity
wt	156-PNIASHISSISARTGDPVTNME-177	6.9	10.4	2,690	260
TLM−	PNIAS------------VTNME	11.9	17.8	2,660	156
S only		13.4	20.1	2.84	0.14

^aThe wt sequence shown is as in shown Fig. 1 and represents that part of the HBV pre-S2 that spans the TLM proposed by Stoeckl et al. (29). The mutation (TLM⁻) was made using a QuikChange kit (Stratagene). Particles assembled with only HBV S protein were used as a negative control for infectivity. The assembly, infectivity, and specific infectivity of HDV were assayed as described in Table 1 and as previously described (16), and all are based on the average of independent, duplicate, quantitative real-time PCR assays of GE. Based on this and a separate experiment, we consider the range of specific infectivity values for wt and TLM⁻ to be not significantly different.