1n4b

[[Image:1n4b.gif|left|200px]]<br /><applet load="1n4b" size="450" color="white" frame="true" align="right" spinBox="true"

caption="1n4b" />

'''Solution Structure of the undecamer CGAAAC*TTTCG'''<br />

==Overview==

The solution structure of an interstrand cross-linked self-complementary, oligodeoxynucleotide containing directly opposed alkylated, N(4)C-ethyl-N(4)C cytosine bases was determined by molecular dynamics, calculations guided by NMR-derived restraints. The undecamer, d(CGAAACTTTCG)(2), where C represents directly opposed alkylated, N(4)C-ethyl-N(4)C cytosine bases, serves as model for the cytotoxic, cross-links formed by bifunctional alkylating agents used in cancer, therapy. The structure of the duplex shows the cross-link protruding into, the major groove. An increase in the diameter of the DNA at the, pseudoplatform formed by the cross-linked residues creates an A-DNA, characteristic hole in the central portion of the DNA. This results in a, centrally underwound base step and a number of subsequent overwinding, steps leading to an overall axis bend toward the major groove. The, structure shows narrowing of both minor and major grooves in the proximity, of the cross-link. The perturbation leads to preferential intrastrand base, stacking, disruption of adjacent canonical (A.T) base pairing, and, buckling of base pairs, the extent of which diminishes with progression, away from the lesion site. Overall, the distortion induced by the, cross-link spreads over three base pairs on the 5'- and 3'-sides of the, cross-link.

 

==About this Structure==

1N4B is a [http://en.wikipedia.org/wiki/Protein_complex Protein complex] structure of sequences from [http://en.wikipedia.org/wiki/ ] with EHN as [http://en.wikipedia.org/wiki/ligand ligand]. Full crystallographic information is available from [http://ispc.weizmann.ac.il/oca-bin/ocashort?id=1N4B OCA].

 

==Reference==

Solution structure of a DNA duplex containing mispair-aligned N4C-ethyl-N4C interstrand cross-linked cytosines., Webba da Silva M, Noronha AM, Noll DM, Miller PS, Colvin OM, Gamcsik MP, Biochemistry. 2002 Dec 24;41(51):15181-8. PMID:[http://ispc.weizmann.ac.il//pmbin/getpm?pmid=12484755 12484755]

[[Category: Protein complex]]

[[Category: Colvin, O.M.]]

[[Category: Gamcsik, M.P.]]

[[Category: Miller, P.S.]]

[[Category: Noll, D.M.]]

[[Category: Noronha, A.M.]]

[[Category: Silva, M.Webba.da.]]

[[Category: EHN]]

[[Category: alkylated cytosine]]

[[Category: alkylated dna]]

[[Category: interstrand cross-link]]

[[Category: modified cytosine]]