FIG. 7.

Alignment of HEMV U3 sequences. (A) The U3 region of the HEMV provirus was obtained as described in the text and is aligned with the corresponding sequences from the X-IV (Mxv11), X-I (NFS-Th-1) (28), P-I (MX27) (49), and ecotropic (Akv) (58) proviruses. Dots indicate nucleotide identity. Dashes indicate absence of a nucleotide. The sequence of an oligonucleotide probe, KT-59/60, reactive with X-IV proviruses is underlined. Direct repeats in the enhancer regions found in ecotropic proviruses are not shown. The PstI recognition site is also shown. (B) Lack of the region 6 direct repeat in HEMV. The 3′ portion of the HEMV U3 sequence is aligned with the analogous regions of the several type C retroviruses. Abbreviations and strains of the viruses included in this alignment are as follows: GaLV-SE and GaLV-SF, SEATO and San Francisco isolates (56); FeLV-A and FeLV-B, feline leukemia virus, subgroup A (Glasgow-1) and subgroup B (Gardner-Arnstein) (48); X-I, NFS-Th-1 (28).