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Strand‐Biased Formation of G‐Quadruplexes in DNA Duplexes Transcribed with T7 RNA Polymerase
Author(s) -
Liu Jiaquan,
Xiao Shan,
Hao Yuhua,
Tan Zheng
Publication year - 2015
Publication title -
angewandte chemie international edition
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.831
H-Index - 550
eISSN - 1521-3773
pISSN - 1433-7851
DOI - 10.1002/anie.201503648
Subject(s) - transcription bubble , transcription (linguistics) , coding strand , g quadruplex , t7 rna polymerase , dna , duplex (building) , rna polymerase , polymerase , rna , biology , chemistry , biophysics , microbiology and biotechnology , gene , genetics , rna dependent rna polymerase , bacteriophage , linguistics , philosophy , escherichia coli
Abstract G‐quadruplex‐forming sequences are enriched near transcription start sites (TSSs) in animal genes. They readily form G‐quadruplexes in transcription, which in turn regulate transcription. Therefore, the control of G‐quadruplex formation is important for their functionality. It is now shown that G‐quadruplexes form efficiently on the non‐template, but hardly on the template DNA strand in the downstream vicinity of TSSs in DNA duplexes when they are transcribed by the T7 RNA polymerase (RNAP). Structural analysis reveals that the T7 RNAP causes distortion in a DNA duplex both inside and in front of the enzyme. This structural distortion leads to strand‐biased G‐quadruplex formation when a G‐quadruplex‐forming sequence is partially fed into the T7 RNAP to a position about seven nucleotides away from the front of RNA synthesis. Based on these facts, we propose a model for the strand‐biased formation of G‐quadruplexes in transcribed DNA duplexes.