2dd2
From Proteopedia
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An alternating sheared AA pair in 5'GGUGAAGGCU/3'PCCGAAGCCG: I. The major conformation with A6/A15/A16 stack
Overview
A previous NMR structure of the duplex 5'GGU GGA GGCU/PCCG AAG CCG5', revealed an unusually stable RNA internal loop with three consecutive, sheared GA pairs. Here, we report NMR studies of two duplexes, 5'GGU GGA, GGCU/PCCA AAG CCG5' (replacing the UG pair with a UA closing pair) and, 5'GGU GAA GGCU/PCCG AAG CCG5' (replacing the middle GA pair with an AA, pair). An unusually stable loop with three consecutive sheared GA pairs, forms in the duplex 5'GGU GGA GGCU/PCCA AAG CCG5'. The structure contrasts, with that reported for this loop in the crystal structure of the large, ribosomal subunit of Deinococcus radiodurans [Harms, J., Schluenzen, F., Zarivach, R., Bashan, A., Gat, S., Agmon, I., Bartels, H., Franceschi, F., and Yonath, A. (2001) Cell 107, 679-688]. The middle AA pair in the duplex, 5'GGU GAA GGCU/PCCG AAG CCG5' rapidly exchanges orientations, resulting in, alternative base stacking and pseudosymmetry with exclusively sheared, pairs. The U GAA G/G AAG C internal loop is 2.1 kcal/mol less stable than, the U GGA G/G AAG C internal loop at 37 degrees C. Structural, energetic, and dynamic consequences upon functional group substitutions within, related 3 x 3 and 3 x 6 internal loops are also reported.
About this Structure
2DD2 is a Protein complex structure of sequences from [1]. Full crystallographic information is available from OCA.
Reference
An alternating sheared AA pair and elements of stability for a single sheared purine-purine pair flanked by sheared GA pairs in RNA., Chen G, Kennedy SD, Qiao J, Krugh TR, Turner DH, Biochemistry. 2006 Jun 6;45(22):6889-903. PMID:16734425
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