Fig. 6.

DIS mutations affect retroviral 5′-leader dimerization. a Structure of the native SIV_cpzTAN1 DIS stem-loop within the intact leader and mutations (red) that extend its native DIS palindrome. b Native agarose gel electrophoresis data obtained for SIV_cpzTAN1 wild-type (5′-L_WT) and mutant leader RNAs (5′-L_GC and 5′-L_{HIV-1 loop}) after 1-h incubation in PI buffer and measured using TB and TBM running buffers. c Structure of the native HIV-2_ROD DIS stem-loop within the intact leader and mutations (red) that obstructs the DIS palindrome (5′-L_CCA) or enhances DIS intermolecular loop–loop interactions (5′-L_{HIV-1 loop}). d Native gel data also obtained for HIV-2_ROD wild-type and mutant leader RNAs. DIS mutations with extended/enhanced DIS palindromes favor the dimer formation, whereas mutation with obstructed DIS palindrome favors the monomer formation