1OSU

STRUCTURE OF THE RNA HEXAMER, R(UUCGCG), WITH A 5'-UU-OVERHANG EXHIBITING HOOGSTEEN-LIKE TRANS U-U BASE PAIRS

Summary for 1OSU

• Entry DOI: 10.2210/pdb1osu/pdb
• Descriptor: RNA (5'-R(*UP*UP*CP*GP*CP*G)-3') (2 entities in total)
• Functional Keywords: a-rna, double helix, nicked, 5'-uu-overhang, mismatched, rna
• Total number of polymer chains: 1
• Total formula weight: 1868.15

Authors

Wahl, M.C.,Rao, S.T.,Sundaralingam, M. (deposition date: 1995-11-08, release date: 1996-04-04, Last modification date: 2024-02-14)

Primary citation

Wahl, M.C.,Rao, S.T.,Sundaralingam, M.
The structure of r(UUCGCG) has a 5'-UU-overhang exhibiting Hoogsteen-like trans U.U base pairs.
Nat.Struct.Biol., 3:24-31, 1996

PubMed Abstract: The crystal structure of the RNA fragment, 5'-r(UUCGCG)-3', has been determined at 1.4 A resolution by a combination of single isomorphous replacement and molecular search methods. The 3'-terminal CGCG portion of the hexamer engages in Watson-Crick hydrogen bonding while the 5'-terminal UU-overhang forms novel Hoogsteen-like U.U self-base pairs with the overhang of an adjacent duplex. The U.U pairs display a single conventional hydrogen bond between O4 (U1) and N3 (U8) and a CH-O hydrogen bond between C5-H (U1) and O4 (U8), through the Hoogsteen face of the pyrimidine base U1. This unusual arrangement of one of the bases results in a trans U.U pair on antiparallel strands in contrast to the usual cis base pairs. The structure emphasizes the pronounced polymorphism of U.U pairs and has implications for folding of RNA molecules.

PubMed: 8548450
DOI: 10.1038/nsb0196-24

Experimental method

X-RAY DIFFRACTION (1.4 Å)