Bubble dynamics in double-stranded DNA.
نویسندگان
چکیده
We report the first measurement of the dynamics of bubble formation in double-stranded DNA. Fluctuations of fluorescence of a synthetic DNA construct, internally tagged with a fluorophore and a quencher, are monitored by fluorescence correlation spectroscopy. The relaxation dynamics follow a multistate relaxation kinetics, with a characteristic time scale of 50 microseconds. A simple model of bubble dynamics based on constant zipping-unzipping rates is proposed to account for our experimental data. The role of different secondary structures stabilizing the open bubble is tested.
منابع مشابه
Bubble coalescence in breathing DNA: Two vicious walkers in opposite potentials
– We investigate the coalescence of two DNA-bubbles initially located at weak segments and separated by a more stable barrier region in a designed construct of double-stranded DNA. The characteristic time for bubble coalescence and the corresponding distribution are derived, as well as the distribution of coalescence positions along the barrier. Below the melting temperature, we find a Kramers-...
متن کاملThe dynamics of intermittent strand separation in double-stranded DNA.
The transient rupture and reformation of hydrogen bonds between base pairs on distinct chains of double-stranded DNA ("bubble" dynamics) is modeled in terms of the fluctuating distance between the bases. The fluctuations in the distance are assumed to be governed by a simple Langevin equation with a quadratic potential under conditions of high friction. A critical distance of separation L must ...
متن کاملMaster equation approach to DNA breathing in heteropolymer DNA.
After crossing an initial barrier to break the first base-pair (bp) in double-stranded DNA, the disruption of further bps is characterized by free energies up to a few k(B)T. Thermal motion within the DNA double strand therefore causes the opening of intermittent single-stranded denaturation zones, the DNA bubbles. The unzipping and zipping dynamics of bps at the two zipper forks of a bubble, w...
متن کاملBubble relaxation dynamics in double-stranded DNA.
This paper deals with the two-state (opening-closing of base pairs) model used to describe the fluctuation dynamics of a single bubble formation. We present an exact solution for the discrete and finite size version of the model that includes end effects and derive analytic expressions of the correlation function, survival probability, and lifetimes for the bubble relaxation dynamics. It is sho...
متن کاملNonlinear waves in double-stranded DNA.
We propose a nonlinear model derived from first principles, to describe bubble dynamics of DNA. Our model equations include a term derived from the dissipative effect of intermolecular vibrational modes. Such modes are excited by the propagating bubble, and we term this 'curvature dissipation'. The equations that we derive allow for stable pinned localized kinks which form the bubble. We perfor...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید
ثبت ناماگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید
ورودعنوان ژورنال:
- Physical review letters
دوره 90 13 شماره
صفحات -
تاریخ انتشار 2003