4K2E
HlyU from Vibrio cholerae N16961
Summary for 4K2E
| Entry DOI | 10.2210/pdb4k2e/pdb |
| Descriptor | Transcriptional activator HlyU (2 entities in total) |
| Functional Keywords | winged helix, dna-binding domain, hemolysin gene transcription regulator, dna, s-hydroxycysteine, transcription activator |
| Biological source | Vibrio cholerae |
| Total number of polymer chains | 4 |
| Total formula weight | 50951.32 |
| Authors | Mukherjee, D.,Datta, A.B.,Chakrabarti, P. (deposition date: 2013-04-09, release date: 2014-04-30, Last modification date: 2024-11-13) |
| Primary citation | Mukherjee, D.,Datta, A.B.,Chakrabarti, P. Crystal structure of HlyU, the hemolysin gene transcription activator, from Vibrio cholerae N16961 and functional implications. Biochim.Biophys.Acta, 1844:2346-2354, 2014 Cited by PubMed Abstract: HlyU in Vibrio cholerae is known to be the transcriptional activator of the hemolysin gene, HlyA and possibly a regulator of other virulence factors influencing growth, colonization and pathogenicity of this infective agent. Here we report the crystal structure of HlyU from V. cholerae N16961 (HlyU_Vc) at 1.8Å. The protein, with five α-helices and three β-strands in the topology of α1-α2-β1-α3-α4-β2-β3-α5, forms a homodimer. Helices α3-α4 and a β sheet form the winged helix-turn-helix (wHTH) DNA-binding motif common to the transcription regulators of the SmtB/ArsR family. In spite of an overall fold similar to SmtB/ArsR family, it lacks any metal binding site seen in SmtB. A comparison of the dimeric interfaces showed that the one in SmtB is much larger and have salt bridges that can be disrupted to accommodate metal ions. A model of HlyU-DNA complex suggests bending of the DNA. Cys38 in the structure was found to be modified as sulfenic acid; the oxidized form was not seen in another structure solved under reducing condition. Although devoid of any metal binding site, the presence of a Cys residue exhibiting oxidation-reduction suggests the possibility of the existence of a redox switch in transcription regulation. A structure-based phylogenetic analysis of wHTH proteins revealed the segregation of metal and non-metal binding proteins as well as those in the latter group that are under redox control. PubMed: 25450504DOI: 10.1016/j.bbapap.2014.09.020 PDB entries with the same primary citation |
| Experimental method | X-RAY DIFFRACTION (1.8 Å) |
Structure validation
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