Interruptions of (CG)n sequences by GG, TG and CA need not prevent B to Z transition in solution.
Oligonucleotides containing alternating purines-pyrimidines with AT base pairs have been shown to exist in the Z-form preferably in solid state. We report that oligodeoxyribonucleotides with GG, TG and CA interruptions in their alternating CG sequences can undergo B to Z transition in solution in the absence of any chemical modification or topological constraint. The sequences, d(CGCGCGGCGCGC) and d(CGTGCGCACG) have been synthesised and shown to adopt Z- conformation in presence of millimolar concentrations of Ni2+ under low water activity conditions. Significance of GG, TG and CA interruptions in the B to Z transition is discussed.
Mishra
R K
RK
Molecular Biophysics Unit, Indian Institute of Science, Bangalore, India.
Latha
P K
PK
Brahmachari
S K
SK
D001483:Base Sequence; D002942:Circular Dichroism; D004247:DNA; D007700:Kinetics; D009690:Nucleic Acid Conformation; D009838:Oligodeoxyribonucleotides; D012996:Solutions; D013056:Spectrophotometry, Ultraviolet; D013329:Structure-Activity Relationship
D009838:Oligodeoxyribonucleotides; D012996:Solutions; D004247:DNA