TY - JOUR

T1 - Spin symmetry transitions make DNA strands separate. New insight into the mechanism of transcription

AU - Tulub, Alexander A.

AU - Stefanov, Vassily E.

N1 - Publisher Copyright: © 2015 IOP Publishing Ltd.

PY - 2015/12/8

Y1 - 2015/12/8

N2 - The DFT:B3LYP (6-31G** basis set) method, including the hyperfine and spin-orbit couplings (HFC and SOC, respectively), is used to study the separation of two complementary trinucleotide sequences, (dC-dG-dA)-(dG-dC-dT), upon the action of two Mg(2+) cofactors (a simplified model). The computations reveal a crossing of the singlet (S) potential energy surface by the triplet (T) surface at two distinct points. Within the crossing region the T curve lies below the S curve. Adhering to the concept of the minimal energy path, one can assume that the T path is more favorable compared to that of the S path. The T path is not simple; it consists of two, T+ and T-, curves initially separated by the HFC and SOC. On reaching the second crossing point, both curves merge into the T0 state, which facilitates the T → S transfer. Totally, the process of the two trinucleotide separation (the first step of transcription) appears as the S → T → S symmetry conversion.

AB - The DFT:B3LYP (6-31G** basis set) method, including the hyperfine and spin-orbit couplings (HFC and SOC, respectively), is used to study the separation of two complementary trinucleotide sequences, (dC-dG-dA)-(dG-dC-dT), upon the action of two Mg(2+) cofactors (a simplified model). The computations reveal a crossing of the singlet (S) potential energy surface by the triplet (T) surface at two distinct points. Within the crossing region the T curve lies below the S curve. Adhering to the concept of the minimal energy path, one can assume that the T path is more favorable compared to that of the S path. The T path is not simple; it consists of two, T+ and T-, curves initially separated by the HFC and SOC. On reaching the second crossing point, both curves merge into the T0 state, which facilitates the T → S transfer. Totally, the process of the two trinucleotide separation (the first step of transcription) appears as the S → T → S symmetry conversion.

KW - DNAtranscription

KW - molecular spintronics

KW - singlet-triplet conversions

UR - http://www.scopus.com/inward/record.url?scp=84953791644&partnerID=8YFLogxK

U2 - 10.1088/1478-3975/12/6/066017

DO - 10.1088/1478-3975/12/6/066017

M3 - Article

C2 - 26656910

VL - 12

JO - Physical Biology

JF - Physical Biology

SN - 1478-3967

IS - 6

M1 - 066017

ER -