High mobility group proteins HMG-1 and HMG-I/Y bind to a positive regulatory region of the pea plastocyanin gene promoter.
A 268 bp region (P268) of the pea plastocyanin gene promoter responsible for high-level expression has been shown to interact with the high mobility group proteins HMG-1 and HMG-I/Y isolated from pea shoot chromatin. cDNAs encoding an HMG-1 protein of 154 amino acid residues containing a single HMG-box and a C-terminal acidic tail and an HMG-I/Y-like protein of 197 amino acid residues containing four AT-hooks have been isolated and expressed in Escherichia coli to provide large amounts of full-length proteins. DNase I footprinting identified eight binding sites for HMG-I/Y and six binding sites for HMG-1 in P268. Inhibition of binding by the antibiotic distamycin, which binds in the minor groove of A/T-rich DNA, revealed that HMG-I/Y binding was 400-fold more sensitive than HMG-1 binding. Binding-site selection from a pool of random oligonucleotides indicated that HMG-I/Y binds to oligonucleotides containing stretches of five or more A/T bp and HMG-1 binds preferentially to oligonucleotides enriched in dinucleotides such as TpT and TpG.
Webster
C I
CI
Cambridge Centre for Molecular Recognition, University of Cambridge, UK.
Packman
L C
LC
Pwee
K H
KH
Gray
J C
JC
D000595:Amino Acid Sequence; D001483:Base Sequence; D001665:Binding Sites / Q000235:genetics; D018983:DNA Footprinting; D017931:DNA Primers / Q000235:genetics; D018076:DNA, Complementary / Q000235:genetics; D018744:DNA, Plant / Q000235:genetics; D004214:Distamycins / Q000494:pharmacology; D004926:Escherichia coli / Q000235:genetics; D017343:Genes, Plant; D025741:HMGA1a Protein; D006609:High Mobility Group Proteins / Q000235:genetics / Q000378:metabolism*; D008969:Molecular Sequence Data; D018532:Pisum sativum / Q000235:genetics* / Q000378:metabolism*; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism*; D010970:Plastocyanin / Q000235:genetics; D011401:Promoter Regions, Genetic; D011485:Protein Binding / Q000187:drug effects
D017931:DNA Primers; D018076:DNA, Complementary; D018744:DNA, Plant; D004214:Distamycins; D006609:High Mobility Group Proteins; D010940:Plant Proteins; D025741:HMGA1a Protein; C030000:stallimycin; D010970:Plastocyanin