Open AccessStructure of the response regulator VicR DNA‐binding domain
Author(s) -
Trinh ChiHung,
Liu Yang,
Phillips Simon E. V.,
PhillipsJones Mary K.
Publication year - 2007
Publication title -
acta crystallographica section d
Language(s) - English
Resource type - Journals
ISSN - 1399-0047
DOI - 10.1107/s0907444906043435
Subject(s) - response regulator , helix turn helix , bacillus subtilis , biology , dna , subfamily , rna polymerase , regulator , protein subunit , dna binding domain , sigma factor , genetics , binding site , dna binding protein , rna , transcription factor , gene , bacteria , bacterial protein
The response regulator VicR from the Gram‐positive bacterium Enterococcus faecalis forms part of the two‐component signal transduction system of the YycFG subfamily. The structure of the DNA‐binding domain of VicR, VicR c , has been solved and belongs to the winged helix–turn–helix family. It is very similar to the DNA‐binding domains of Escherichia coli PhoB and OmpR, despite low sequence similarity, but differs in two important loops. The α‐loop, which links the two helices of the helix–turn–helix motif, is similar to that of PhoB, where it has been implicated in contacting the σ subunit of RNA polymerase, but differs from that of OmpR. Conversely, the loop following the helix–turn–helix motif is similar to that of OmpR and differs from that of PhoB. YycF/VicR, PhoB and Bacillus subtilis PhoP regulators all recognize almost identical DNA sequences and although there is currently no experimental evidence linking this loop with the DNA, the structure is consistent with possible involvement in selective DNA recognition or binding.