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Helix–coil transition in nucleoprotein—theory and applications
Author(s) -
Li Hsueh Jei
Publication year - 1973
Publication title -
biopolymers
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.556
H-Index - 125
eISSN - 1097-0282
pISSN - 0006-3525
DOI - 10.1002/bip.1973.360120207
Subject(s) - nucleoprotein , dna , chemistry , helix (gastropod) , random coil , nucleotide , base pair , histone , polylysine , crystallography , stereochemistry , biochemistry , circular dichroism , biology , ecology , snail , gene
A general theory of helix–coil transition of irreversibly complexed nucleoproteins is presented. The equations are tested by experimental results in basic polypeptide–DNA complexes, nucleohistone I and pea bud nucleohistones. They show good agreement between theory and experiments. The theory provides direct measurement of a fraction of DNA base pairs covered by proteins, yielding a value of about 75% histone‐covered base pairs in pea bud nucleohistone. It also provides a measurement of an average number of amino acid residues per nucleotide in protein‐bound regions. This number varies from 1.0 to 1.4 in DNA–polylysine or DNA–polyarginine and from 2.9 to 3.3 in nucleohistone Ia, Ib, f1, and pea bud nucleohistone.