Sequence specificity in spermine-induced structural changes in CG-oligomers
Majumder, K.; Brahmachari, S.K.
Biochemistry International 18(2): 455-465
1989
ISSN/ISBN: 0158-5231 PMID: 2764957 Document Number: 344787
The role of spermine in inducing A-DNA conformation in deoxyoligonucleotides has been studied using CCGG and GGCC as model sequences. It has been found that while CCGG adopts an alternating B-DNA conformation in low salt solution at low temperature, addition of spermine to this medium induces a B --greater than A transition. In contrast, the A-DNA-like structure of GGCC in low salt solution at low temperature does not change under the influence of spermine. This suggests a sequence-dependent behaviour of spermine. Further these results suggest that the A-DNA conformation observed in the crystals of d(iCCGG) and d(GGCC)2 might have been due to the presence of spermine in the crystallization cocktail.