'''CRYSTAL AND MOLECULAR STRUCTURE OF A DNA FRAGMENT: D(CGTGAATTCACG)'''
===CRYSTAL AND MOLECULAR STRUCTURE OF A DNA FRAGMENT: D(CGTGAATTCACG)===
==Overview==
<!--
The crystal structure of the dodecanucleotide d(CGTGAATTCACG) has been determined to a resolution of 2.7 A and refined to an R factor of 17.0% for 1532 reflections. The sequence crystallizes as a B-form double helix, with Watson-Crick base pairing. This sequence contains the EcoRI restriction endonuclease recognition site, GAATTC, and is flanked by CGT on the 5'-end and ACG on the 3'-end, in contrast to the CGC on the 5'-end and GCG on the 3'-end in the parent dodecamer d(CGCGAATTCGCG). A comparison with the isomorphous parent compound shows that any changes in the structure induced by the change in the sequence in the flanking region are highly localized. The global conformation of the duplex is conserved. The overall bend in the helix is 10 degrees. The average helical twist values for the present and the parent structures are 36.5 degrees and 36.4 degrees, respectively, corresponding to 10 base pairs per turn. The buckle at the substituted sites are significantly different from those seen at the corresponding positions in the parent dodecamer. Step 2 (GpT) is underwound with respect to the parent structure (27 degrees vs 36 degrees) and step 3 (TpG) is overwound (34 degrees vs 27 degrees). There is a spine of hydration in the narrow minor groove. The N3 atom of adenine on the substituted A10 and A22 bases are involved in the formation of hydrogen bonds with other duplexes or with water; the N3 atom of guanine on G10 and G22 bases in the parent structure does not form hydrogen bonds.
The line below this paragraph, {{ABSTRACT_PUBMED_2021634}}, adds the Publication Abstract to the page
(as it appears on PubMed at http://www.pubmed.gov), where 2021634 is the PubMed ID number.
-->
{{ABSTRACT_PUBMED_2021634}}
==About this Structure==
==About this Structure==
Line 26:
Line 30:
[[Category: B-dna]]
[[Category: B-dna]]
[[Category: Double helix]]
[[Category: Double helix]]
''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Fri May 2 13:22:00 2008''
''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Mon Jun 30 22:10:40 2008''
Revision as of 22:10, 30 June 2008
This article has been automatically seeded. Changes to this page should pertain to the PDB entry only and not to the protein or biomolecule in general.
Full crystallographic information is available from OCA.
ReferenceReference
Crystal and molecular structure of a DNA fragment: d(CGTGAATTCACG)., Narayana N, Ginell SL, Russu IM, Berman HM, Biochemistry. 1991 May 7;30(18):4449-55. PMID:2021634
