Download MendeleyDestabilizing effect of a fluorouracil extra base in a hybrid RNA duplex compared with bromo and chloro analogues.
Cruse, W., Saludjian, P., Neuman, A., Prange, T.(2001) Acta Crystallogr D Biol Crystallogr 57: 1609-1613
- PubMed: 11679725
- DOI: https://doi.org/10.1107/s0907444901012318
- Primary Citation of Related Structures:
1ICG, 1ID9, 1IDW, 1IHA - PubMed Abstract:
In the presence of cobalt, rhodium or iridium hexammine salts, the RNA/DNA hybrid r-GCUUCGGC-d(X)U (with X = F, Cl or Br) crystallizes as a double-stranded helix with four consecutive G-U and C-U mismatches. The deoxy chloro- and bromouracil derivatives are isomorphous, space group C2, unit-cell parameters a = 53.80, b = 19.40, c = 50.31 A, beta = 109.9 degrees, with the same infinite helix arrangement in the packing along the c axis with one extra DNA halogenouracil base included in the stacking. However, the fluorouracil derivative, with unit-cell parameters a = 53.75, b = 19.40, c = 45.84 A, beta = 105.7 degrees, is not isomorphous. The corresponding extra DNA base d(F)U of the second strand is ejected out of the helical stack, leading to a shortening of the c axis. The specific destabilization of the fluorouracil for the duplex building is analyzed in terms of the polarization effect of the halogen atom attached to the 3'-terminal base that modulates its interactions.
Organizational Affiliation:
CSSB - Chimie Structurale Biomoléculaire (UPRES A7031 CNRS), UFR Biomédicale 74, Rue Marcel Cachin, 93017 Bobigny CEDEX, France.
