FIG 4.

Cluster sso3138 to sso3141 and cluster sso2386 and sso2387 are involved in SIRV2 entry. (A) Growth retardation of sso3139-complemented Res1 upon SIRV2 infection. Res1 (pEXA), Res1 transformed with expression vector pEXA; Res1 (pEXA3139), Res1 transformed with expression vector pEXA containing sso3139. (B) Growth retardation of sso2386-and-sso2387-complemented Res1B upon SIRV2 infection. Res1B (pEXA), Res1B transformed with expression vector pEXA; Res1B (pEXA2386–2387), Res1B transformed with expression vector pEXA containing sso2386 and sso2387. (C and D) Visualization of SIRV2 DNA replication in Res1 (C) and Res1B (D) transformants infected with SIRV2. Plasmid constructs contained in the transformants are labeled on top of each lane, and the sampling time p.i. is indicated as hours. L and R designate the left and right terminal fragments, respectively, after a double digestion with BamHI and HindIII (see panel E). (E) Schematic presentation of SIRV2 genomic map and the formation of terminal duplex replicative intermediates (2L and 2R), as described previously (12). The locations of the probe (filled rectangle) in the termini are indicated. ITR, inverted terminal repeat. (F) RT-PCR amplification of sso0446 (tfb-1) (left panel) and SIRV2 ORF131a transcript fragments (right panel). “+” and “−” indicate the presence and absence of reverse transcriptase (RT), respectively.