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Biophysics One Molecule at a Time
Author(s) -
Bustamante Carlos,
Chen Zhijie
Publication year - 2021
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.2021.35.s1.00065
Subject(s) - chromatin , nucleosome , histone , biophysics , dna , gene expression , computational biology , polymerase , molecule , microbiology and biotechnology , gene , rna polymerase ii , chemistry , biology , physics , genetics , promoter , organic chemistry
Single molecule approaches have become the methods of choice to study the operation of many of the cell's molecular machines. I will describe briefly the advantage of these methods over their bulk counterparts, before discussing one particular case study: the crossing of the nucleosomal barrier by a single molecule of RNA polymerase II. I will show that the dynamics of the crossing process is largely determined by the inability of the enzyme to separate the DNA from the surface of the histone core and its operation, instead, as a rectifier of the fluctuations experienced by the nucleosome structure. As a fundamental mechanism of control of gene expression, the magnitude of the barrier is the subject of regulation through epi‐genetic modifications of chromatin. At the end I present some of the questions that need to be answered in order to garner a more complete picture of how chromatin structure and its chemical modification regulate gene expression.