A new model for DNA containing A.T and I.C base pairs.
AUTOR(ES)
Drew, H R
RESUMO
DNA polymers containing exclusively A.T or I.C base pairs frequently exhibit D- or E-type X-ray diffraction patterns when dried. The distribution of intensities in fiber patterns appears to demand helical structures with 7 and 7.5 bp/turn, respectively, but it is not stereochemically possible to wind a right-handed antiparallel B-family helix this tightly. It is a simple matter, however, to build a left-handed helix with 7-7.5 bp/turn by incorporating Hoogsteen pairing into a Z helix framework. X-ray intensities calculated from this novel left-handed Hoogsteen model provide as reasonable a fit to the D-DNA diffraction pattern as do intensities calculated from previously proposed right-handed 8-fold models.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=553265Documentos Relacionados
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