FIG. 1.

MMLV cis- and trans-acting packaging elements. (A) The MMLV genome. The three MMLV protein-coding sequences are marked, as are the splice donor (SD) and splice acceptor (SA) sites. (B) Diagram of the MMLV Gag protein. Major domains are labeled, as well as the amino-terminal myristyl group (Myr). The position of the zinc finger in NC is indicated by the hatched box. (C) RNA sequence and structures of the extended MMLV packaging signal. SL-A to SL-D and potential Pol III terminator sequences (T1 to T4) are labeled. Sequences that may interact to form tertiary structures are indicated by arrows underneath the sequence.