Summary information and primary citation
- PDB-id
- 237d; DSSR-derived features in text and JSON formats
- Class
- DNA
- Method
- X-ray (2.5 Å)
- Summary
- Crystal structure of a DNA decamer showing a novel pseudo four-way helix-helix junction
- Reference
- Spink N, Nunn CM, Vojtechovsky J, Berman HM, Neidle S (1995): "Crystal structure of a DNA decamer showing a novel pseudo four-way helix-helix junction." Proc.Natl.Acad.Sci.USA, 92, 10767-10771. doi: 10.1073/pnas.92.23.10767.
- Abstract
- The crystal structure of the decanucleotide d(CGCAATTGCG)2 has been solved by a combination of molecular replacement and heavy-atom procedures and has been refined to an R factor of 20.2% at 2.7 A. It is not a fully base-paired duplex but has a central core of eight Watson-Crick base pairs flanked by unpaired terminal guanosines and cytosines. These participate in hydrogen-bonding arrangements with adjacent decamer duplexes in the crystal lattice. The unpaired guanosines are bound in the G+C regions of duplex minor grooves. The cytosines have relatively high mobility, even though they are constrained to be in one region where they are involved in base-paired triplets with G.C base pairs. The 5'-AATT sequence in the duplex region has a narrow minor groove, providing further confirmation of the sequence-dependent nature of groove width.