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Structure of FocB – a member of a family of transcription factors regulating fimbrial adhesin expression in uropathogenic Escherichia coli
Author(s) -
Hultdin Ulrika W.,
Lindberg Stina,
Grundström Christin,
Huang Shenghua,
Uhlin Bernt Eric,
SauerEriksson A. Elisabeth
Publication year - 2010
Publication title -
the febs journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.981
H-Index - 204
eISSN - 1742-4658
pISSN - 1742-464X
DOI - 10.1111/j.1742-4658.2010.07742.x
Subject(s) - homomeric , fimbria , dna , biology , gene , transcription (linguistics) , escherichia coli , transcription factor , bacterial adhesin , genetics , microbiology and biotechnology , protein subunit , linguistics , philosophy
In uropathogenic Escherichia coli , UPEC, different types of fimbriae are expressed to mediate interactions with host tissue. FocB belongs to the PapB family of transcription factors involved in the regulation of fimbriae gene clusters. Recent findings suggest that members from this family of proteins may form homomeric or heteromeric complexes and exert both positive and negative effects on the transcription of fimbriae genes. To elucidate the detailed function of FocB, we have determined its crystal structure at 1.4 Å resolution. FocB is an all α‐helical protein with a helix‐turn‐helix motif. Interestingly, conserved residues important for DNA‐binding are located not in the postulated recognition helix of the motif, but in the preceding helix. Results from protein–DNA‐binding studies suggest that FocB interacts with the minor groove of its cognate DNA target, which is indicative of a DNA interaction that is unusual for this motif. FocB crystallizes in the form of dimers. Packing interactions in the crystals give two plausible dimerization interfaces. Conserved residues, known to be important for protein oligomerization, are present at both interfaces, suggesting that both sites could play a role in a functional FocB protein. Structured digital abstract• MINT‐7901626 : focB (uniprotkb: Q93K76 ) and focB (uniprotkb: Q93K76 ) bind ( MI:0407 ) by x‐ray crystallography ( MI:0114 )