FIG. 4.

Partial RT protein sequence alignment. Sequence names correspond to the GenBank identifiers for ERVs, while common names are used for infectious retroviruses (with their GenBank identifiers given in Fig. 3 and 5 and their legends). The order of the sequences is the same as that for the RT tree (Fig. 4, right). Underlined positions correspond to insertions, and dashes correspond to deletions. The first five common peptide domains among the seven domains described by Xiong and Eickbush (51) are delineated below the sequences (the fifth is partial).