A reported archaeal mechanosensitive channel is a structural homolog of MarR-like transcriptional regulators.
Several archaeal mechanosensitive (MS) channels have been reported, including one from Thermoplasma volcanium designated MscTV. Here, we report the crystal structure of MscTV at 1.6-A resolution. Unexpectedly, MscTV was found to be a water-soluble protein exhibiting a winged helix-turn-helix (wHTH) motif, which is the signature of the MarR (multiple antibiotic resistance regulator) family of transcriptional regulators. A cell-based osmotic downshock functional assay demonstrated that MscTV was unable to protect a knockout strain of Escherichia coli from hypoosmotic shock, further indicating that it does not function as a MS channel. We propose this protein be renamed MLPTv for MarR-like protein from T. volcanium.
Liu
Zhenfeng
Z
Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, California 91125, USA.
Walton
Troy A
TA
Rees
Douglas C
DC
D000595:Amino Acid Sequence; D019843:Archaeal Proteins / Q000737:chemistry* / Q000235:genetics; D018360:Crystallography, X-Ray; D008958:Models, Molecular; D008969:Molecular Sequence Data; D011487:Protein Conformation; D016415:Sequence Alignment; D013822:Thermoplasma / Q000378:metabolism*; D014157:Transcription Factors / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D014158:Transcription, Genetic
D019843:Archaeal Proteins; D014157:Transcription Factors