THE CENTERS OF PREMELTONS SIGNAL THE BEGINNING AND ENDS OF GENES
Joint Event on International Conference on STRUCTURAL BIOLOGY AND PROTEOMICS & International Conference on STD-AIDS AND INFECTIOUS DISEASES
September 03-04, 2018 | Bangkok ,Thailand
Henry M Sobell
University of Rochester, USA
Keynote : J Genet Mol Biol
Premeltons are examples of emergent structures (i.e. structural solitons) that arise spontaneously in DNA due to the presence of nonlinear excitations in its structure. They are of two kinds: B-B (or A-A) premeltons form at specific DNA regions to nucleate site-specific DNA melting. These are stationary and being globally nontopological, undergo breather motions that allow drugs and dyes to intercalate into DNA. B-A (or A-B) premeltons, on the other hand, are mobile and being globally topological, act as phaseboundaries transforming B-DNA into A-DNA during the structural phasetransition. They are not expected to undergo breather-motions. A key feature of both types of premeltons is the presence of an intermediate structural form in their central regions (proposed as being a transition state intermediate in DNA-melting and in the B- to A- transition), which differs from either A- or BDNA called beta-DNA, this is both metastable and hyperflexible and contains an alternating sugar-puckering pattern along the polymer-backbone combined with the partial-unstacking (in its lower energy-forms) of every other base-pair. Beta-DNA is connected to either B- or to A- DNA on either side by boundaries possessing a gradation of nonlinear structural-change, these being called the kink and the antikink regions. The presence of premeltons in DNA leads to a unifying theory to understand much of DNA physical-chemistry and molecularbiology. Premeltons are predicted to define the 5’ and 3’ ends of genes in naked-DNA and DNA in active-chromatin, this having important implications for understanding physical aspects of the initiation, elongation and termination of RNA-synthesis during transcription. For these and other reasons, the model will be of broader interest to the general audience working in these areas. The model explains a wide variety of data and carries within it several experimental predictions, all readily testable and will be described in my talk.
Henry M Sobell has completed his studies at Brooklyn Technical High School (1948-1952), Columbia College (1952-1956) and the University of Virginia School of Medicine (1956-1960). Instead of practicing clinical medicine, he went to the Massachusetts Institute of Technology (MIT) to join Professor Alexander Rich in the Department of Biology (1960-1965) and Helen Hay Whitney, postdoctoral fellow, where he learned the technique of single crystal x-ray analysis. He then joined the Chemistry Department at the University of Rochester, having been subsequently jointly appointed to both the Chemistry and Molecular Biophysics departments, becoming a full tenured Professor in both the departments (1965-1993).
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