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Kinetic studies on the cyclization of T7 and T1 DNA's
Author(s) -
Lee C. S.,
Pyeritz R. E.,
Thomas C. A.
Publication year - 1976
Publication title -
biopolymers
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.556
H-Index - 125
eISSN - 1097-0282
pISSN - 0006-3525
DOI - 10.1002/bip.1976.360150407
Subject(s) - chemistry , dna , reaction rate constant , molecule , nucleotide , kinetics , diffusion , viscosity , stereochemistry , solvent , computational chemistry , thermodynamics , organic chemistry , biochemistry , physics , quantum mechanics , gene
The rates of cyclization of two terminally repetitious phage DNA molecules, T7 and T1, were determined and compared with earlier studies of λ DNA. Though differing over 200‐fold in the number of complementary nucleotides in the single‐chain terminals, these three DNA's cyclize at about comparable rates, suggesting that excluded volume effects are significant. The first order rate constants for T7 and T1 are strictly dependent on solvent viscosity, consistent with a diffusion limitation of the rate determining step. Whole molecules with exposed single‐chain terminals were shear‐broken to half‐molecules and the second order rate constants for joining were measured. The rates for T7 and T1 were nearly equivalent and some tenfold slower than predicted, suggesting that the long double‐helical region appended to the renaturing regions and perhaps other undetermined factors retard the rate of joining of half‐molecules.