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Biochemistry & Molecular Biology Journal
ISSN: 2471-8084
E u r o S c i C o n c o n f e r e n c e o n
Protein, Proteomics and
Computational Biology
D e c e m b e r 0 6 - 0 7 , 2 0 1 8
Am s t e r d a m , N e t h e r l a n d s
P
remeltons 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 phase-
boundaries transforming B- into A- DNA during the structural phase-transition.
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 B- DNA.
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 molecular-
biology. In particular, 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 a
number of experimental predictions – all readily testable – as will be described
in my talk.
Biography
Henry M. Sobell 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 then went to the
Massachusetts Institute of Technology (MIT) to join Professor
Alexander Rich in the Department of Biology (1960-1965),
where, as a Helen Hay Whitney Postdoctoral Fellow, 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 (the latter at the University
of Rochester School of Medicine and Dentistry), becoming a full
tenured Professor in both departments (1965-1993). He is now
retired and living in the Adirondacks in New York, USA.
sobell@localnet.comThe centers of premeltons signal the beginning and ends of genes
Henry M. Sobell
University of Rochester, USA
Henry M. Sobell, Biochem Mol biol J Volume:4
DOI: 10.21767/2471-8084-C5-021