3ZQC

Structure of the Trichomonas vaginalis Myb3 DNA-binding domain bound to a promoter sequence reveals a unique C-terminal beta-hairpin conformation

Summary for 3ZQC

• Entry DOI: 10.2210/pdb3zqc/pdb
• Descriptor: MYB3, MRE-1, ... (4 entities in total)
• Functional Keywords: transcription-dna complex, dna-binding protein, nucleus, transcription/dna
• Biological source: TRICHOMONAS VAGINALIS; More
• Total number of polymer chains: 12
• Total formula weight: 100687.98

Authors

Wei, S.-Y.,Lou, Y.-C.,Tsai, J.-Y.,Hsu, H.-M.,Tai, J.-H.,Hsiao, C.-D.,Chen, C. (deposition date: 2011-06-09, release date: 2012-04-18, Last modification date: 2023-12-20)

Primary citation

Wei, S.-Y.,Lou, Y.-C.,Tsai, J.-Y.,Ho, M.R.,Chou, C.C.,Rajasekaran, M.,Hsu, H.-M.,Tai, J.-H.,Hsiao, C.-D.,Chen, C.
Structure of the Trichomonas Vaginalis Myb3 DNA-Binding Domain Bound to a Promoter Sequence Reveals a Unique C-Terminal Beta-Hairpin Conformation.
Nucleic Acids Res., 40:449-, 2012

PubMed Abstract: Trichomonas vaginalis Myb3 transcription factor (tvMyb3) recognizes the MRE-1 promoter sequence and regulates ap65-1 gene, which encodes a hydrogenosomal malic enzyme that may play a role in the cytoadherence of the parasite. Here, we identified tvMyb3(53-180) as the essential fragment for DNA recognition and report the crystal structure of tvMyb3(53-180) bound to MRE-1 DNA. The N-terminal fragment adopts the classical conformation of an Myb DNA-binding domain, with the third helices of R2 and R3 motifs intercalating in the major groove of DNA. The C-terminal extension forms a β-hairpin followed by a flexible tail, which is stabilized by several interactions with the R3 motif and is not observed in other Myb proteins. Interestingly, this unique C-terminal fragment does not stably connect with DNA in the complex structure but is involved in DNA binding, as demonstrated by NMR chemical shift perturbation, (1)H-(15)N heteronuclear-nuclear Overhauser effect and intermolecular paramagnetic relaxation enhancement. Site-directed mutagenesis also revealed that this C-terminal fragment is crucial for DNA binding, especially the residue Arg(153) and the fragment K(170)KRK(173). We provide a structural basis for MRE-1 DNA recognition and suggest a possible post-translational regulation of tvMyb3 protein.

PubMed: 21908401
DOI: 10.1093/NAR/GKR707

Experimental method

X-RAY DIFFRACTION (2.9 Å)