Figure 1.

Illustration of (A) sequence and (B) structure of the pRNA dimer. The same letters in upper and lower case indicate complementary sequences for the pRNA loop/loop interaction, while different letters indicate noncomplementary loops. For example, pRNA Ab′ represents pRNA where right loop A (5′G45G46A47C48) is complementary to left loop a′ (3′C85C84U83G82) of pRNA Ba′; and left loop b′ (3′U85G84C83G82) is complementary to right loop B (5′A45C46G47C48). The RNA1 and RNA2 were assembled into dimer via the interlocking loops. Numbers in green represent the six donor positions in subunit Ab′ and numbers in red represent the two acceptor positions in subunit Ba′ in two different dimers (see 2).