Binding of the fur (ferric uptake regulator) repressor of Escherichia coli to arrays of the GATAAT sequence.

摘要: The mode of DNA binding the Fur (ferric uptake regulator) repressor which controls transcription iron-responsive genes in Escherichia coli, has been re-examined. Using as a reference known sites at promoter aerobactin operon we have compared detail patterns interaction between purified protein and natural or synthetic targets. DNase I hydroxyl radical footprinting, well missing-T assays, consistently revealed that functional are composed minimum three repeats hexameric motif GATAAT rather than by palindromic 19 bp target sequence. Extended sites, constructed stepwise addition one two direct same sequence, were occupied co-operatively with pattern interactions those observed core repeats. This indicated range affinities can be formed discrete extensions to minimal recognition fashion binds its target, virtually unknown prokaryotic transcriptional regulators, accounts for helical wrapping around helix.