3OSF : The structure of protozoan parasite Trichomonas vaginalis Myb2 in complex with MRE-2f-13 DNA

  • Ingjye Jiang (Contributor)
  • Cheng K. Tsai (Contributor)
  • Sheng Chia Chen (Contributor)
  • Szu Huan Wang (Contributor)
  • Imamaddin Amiraslanov (Contributor)
  • Chi Fon Chang (Contributor)
  • Wen Jin Wu (Contributor)
  • Jung Hsiang Tai (Contributor)
  • Yen Chywan Liaw (Contributor)
  • Tai-huang Huang (Contributor)



Experimental Technique/Method:X-RAY DIFFRACTION
Release Date:2011-08-03
Deposition Date:2010-09-09
Revision Date:2013-08-28
Molecular Weight:45714.64
Macromolecule Type:Protein#DNA
Residue Count:304
Atom Site Count:2770

Iron-inducible transcription of the ap65-1 gene in Trichomonas vaginalis involves at least three Myb-like transcriptional factors (tvMyb1, tvMyb2 and tvMyb3) that differentially bind to two closely spaced promoter sites, MRE-1/MRE-2r and MRE-2f. Here, we defined a fragment of tvMyb2 comprising residues 40-156 (tvMyb2₄₀₋₁₅₆) as the minimum structural unit that retains near full binding affinity with the promoter DNAs. Like c-Myb in vertebrates, the DNA-free tvMyb2₄₀₋₁₅₆ has a flexible and open conformation. Upon binding to the promoter DNA elements, tvMyb2₄₀₋₁₅₆ undergoes significant conformational re-arrangement and structure stabilization. Crystal structures of tvMyb2₄₀₋₁₅₆ in complex with promoter element-containing DNA oligomers showed that 5'-a/gACGAT-3' is the specific base sequence recognized by tvMyb2₄₀₋₁₅₆, which does not fully conform to that of the Myb binding site sequence. Furthermore, Lys⁴⁹, which is upstream of the R2 motif (amino acids 52-102) also participates in specific DNA sequence recognition. Intriguingly, tvMyb2₄₀₋₁₅₆ binds to the promoter elements in an orientation opposite to that proposed in the HADDOCK model of the tvMyb1₃₅₋₁₄₁/MRE-1-MRE-2r complex. These results shed new light on understanding the molecular mechanism of Myb-DNA recognition and provide a framework to study the molecular basis of transcriptional regulation of myriad Mybs in T. vaginalis.
Date made available2011
PublisherUnknown Publisher

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