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In vitro DNA‐binding properties of VirB, the Shigella flexneri virulence regulatory protein
Author(s) -
McKenna Sorcha,
Beloin Christophe,
Dorman Charles J.
Publication year - 2003
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 - 10.1016/s0014-5793(03)00524-6
Subject(s) - shigella flexneri , leucine zipper , dna , dna binding domain , transcription factor , dna binding protein , helix turn helix , dna binding site , mutant , biology , chemistry , siphoviridae , bzip domain , biochemistry , promoter , gene , escherichia coli , bacteriophage , gene expression
The DNA‐binding activity of the Shigella flexneri VirB transcription factor was studied in vitro. The protein was found to bind non‐specifically to DNA, but showed preferential binding to VirB‐dependent promoter sequences. DNA binding was contingent on the presence of an intact helix‐turn‐helix motif. While high molecular mass protein–DNA complexes were formed in both specific and non‐specific interactions with DNA, mutant derivatives of VirB lacking a leucine zipper domain or a carboxyl‐terminal‐located oligomerisation domain formed discrete complexes, indicating that an ability to oligomerise on DNA was responsible for the formation of high molecular mass complexes by the wild‐type protein.