Volume 272, Number 42,
Issue of October 17, 1997
pp. 26578-26584
©1997 by The American Society for Biochemistry and Molecular Biology, Inc.
Pairing of DNA Fragments Containing (GGA:TCC)n Repeats
and Promotion by High Mobility Group Protein 1 and Histone H1
(Received for publication, June 12, 1997, and in revised form, August 6, 1997)
Yukio
Mishima
,
Hidetoshi
Kaizu
and
Ryo
Kominami
From the Department of Biochemistry, Niigata University School of
Medicine, Asahimachi-dori 1-757, Niigata 951, Japan
Tandemly repeated DNA sequences of
(GGA:TCC)n are found in tracts up to 50 base pairs long,
dispersed at thousands of sites throughout the genomes of eukaryotes.
Here we demonstrate the formation of complexes paired between two DNAs
containing such repeats in vitro and show enhancement of
the pairing by glutathione S-transferase fusion proteins of
high mobility group protein 1 and histone H1. This assembly depends on
incubation time at 37 °C and concentrations of the proteins and DNA,
and the enhancement is inhibited by distamycin and actinomycin D
interacting DNA through the minor groove. Structure of the DNA-DNA
complex is deduced by comparison of its mobility in gel electrophoresis
with those of synthetic markers of heterotetramers. Three synthetic and
genomic DNA fragments containing repeats that have different
arrangements exhibit different efficiencies of DNA pairing, implying
that the pairing is affected by the number of repeat units and the
arrangement of repeats in a sequence. Intriguingly, pairing occurs
between homologous fragments but not between heterologous DNAs among
the three. These results suggest that the repeat-mediated DNA pairing plays a role in organization of higher order architecture of chromatin and possibly chromosome segregation requiring sequence-specific association events of DNA molecules.
CiteULike 
Complore 
Connotea 
Del.icio.us 
Digg 
Reddit 
Technorati What's this?
