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A structural sketch of RcdA, a transcription factor controlling the master regulator of biofilm formation
Author(s) -
Sugino Hirotaka,
Usui Takanori,
Shimada Tomohiro,
Nakano Masahiro,
Ogasawara Hiroshi,
Ishihama Akira,
Hirata Akira
Publication year - 2017
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1002/1873-3468.12713
Subject(s) - regulator , dna , docking (animal) , master regulator , dna binding domain , chemistry , mutagenesis , transcription factor , biophysics , transcription (linguistics) , gene , biology , biochemistry , mutation , medicine , linguistics , philosophy , nursing
RcdA is a regulator of curlin subunit gene D, the master regulator of biofilm formation in Escherichia coli . Here, we determined the X‐ray structure of RcdA at 2.55 Å resolution. RcdA consists of an N‐terminal DNA ‐binding domain ( DBD ) containing a helix‐turn‐helix ( HTH ) motif and a C‐terminal dimerization domain, and forms a homodimer in crystals. A computational docking model of the RcdA‐ DNA complex allowed prediction of the candidate residues responsible for DNA binding. Our structure‐guided mutagenesis, in combination with gel shift assay, atomic force microscopic observation, and reporter assay, indicate that R32 in α2 of the HTH motif plays an essential role in the recognition and binding of target DNA while T46 in α3 influences the mode of oligomerization. These results provide insights into the DNA ‐binding mode of RcdA.