Fig. 1

Structural properties of full-length VL30 elements. A representative VL30 element is depicted, using sequence data from UCSC genome browser, LTR-finder and additional BLAST searches. Depicted from 5′ to 3′: LTRs: Long Terminal Repeats, PBS: Primer Binding Site; PSF-BM: PSF Binding Motif; Gag, Pol: regions related to retroviral genes (but contain multiple stop-codons); PPT: Poly-Purine Tract; TSD: Target Site Duplication. Gly, Gln, Pro, Met and Thr indicate tRNA species complementary to PBS signals of VL30 elements, while in parentheses is shown the number of elements that use each tRNA. Below PSF-BM are presented the sequences of the two specific motifs of PSF binding, while below PPT region the 15-bp consensus sequence