  The relationship of base pair openings to DNA flexibility is examined.
Published experimental data on the temperature dependence of the persistence
length by two different groups are well described in terms of an inhomogeneous
Kratky-Porot model with soft and hard joints, corresponding to open and closed
base pairs, and sequence-dependent statistical information about the state of
each pair provided by a Peyrard-Bishop-Dauxois (PBD) model calculation with no
freely adjustable parameters.
