Química Industrial: Acesso Aberto

Abstrato

The Centers of Premeltons Signal the Beginning and Ends of Genes- Henry M Sobell- University of Rochester

Henry M Sobell

Statement of the Problem:

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.

Aim: 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.

Findings:  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 ofRNA-synthesis during transcription.

 

 

 

 

 

Note: This work was presented in Frontiers in Nanotechnology and Nanomaterials, which was scheduled in May 04-05, 2020 at Vienna, Austria.