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Structure of a six-finger transcription factor IIIA complex In DNA recognition

Structure of a six-finger transcription factor IIIA complex In DNA recognition. Hui Pengtao Advisor: Dr. Li. Structure of a six-finger transcription factor IIIA complex. Zinc fingers. * Positioned in the major groove and across the minor groove of DNA * Span the entire length of the duplex

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Structure of a six-finger transcription factor IIIA complex In DNA recognition

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  1. Structure of a six-finger transcription factor IIIA complex In DNA recognition Hui Pengtao Advisor: Dr. Li

  2. Structure of a six-finger transcription factor IIIA complex

  3. Zinc fingers *Positioned in the major groove and across the minor groove of DNA *Span the entire length of the duplex *Showhow TFIIIA can recognize separated DNA sequences in the major groove. Proc Natl Acad Sci U S A. 1998 March 17; 95(6): 2938–2943. Differing roles for zinc fingers in DNA recognition: Structure of a six-finger transcription factor IIIA complex

  4. Zinc fingers 2007221107100008 02.pse 2007221107100008 03.pse

  5. TFIIIA complex(transcription factor IIIA complex ) The tripartite promoter containing *box A * intermediate element (IE) * box C sequences

  6. Description of TFIIIAStructure *Six-finger protein stretches along the entire length of the 31-bp duplex *The current protein model includes amino acids 10–188 of TFIIIA *fingers 1–2–3 adopt a completely different configuration than do fingers 4–5–6 (A)

  7. Six-fingers Different configuration 2007221107100008 01.pse

  8. Six-fingers * 1 Fingers 1–2–3 are separated by typical linker sequences, wrap smoothly around the major groove 2 Contacts are made with DNA bases mainly on the noncoding strand of the 5S rRNA gene. * 1 Fingers 4–5–6, run along one side of the DNA double helix, form an open, extended structure. 2 only finger 5 makes contacts with bases in the major groove. 3 The two flanking fingers, 4 and 6, straddle the neighboring minor grooves.

  9. Six-fingers Crystallographic assignment of zinc fingers and DNA bases to locations within the complex

  10. Six-fingers • Each TFIIIA finger is folded in the classical way around a Zn(II) ion • Zinc finger binding there are increases in the depth and width of the major groove

  11. Linker sequence * The consensus pentapeptide linker sequence Thr-Gly-Glu-Lys-Pro * associate with major-groove binding fingers * appear only twice in this NH2-terminal segment of TFIIIA

  12. Zinc Finger–DNA Interactions DNA major-groove contacts with each of the zinc fingers 1, 2, 3, and 5

  13. TFIIIA–DNA complex The structure of the TFIIIA–DNA complex shows how zinc fingers have been deployed to bind to separated promoter elements

  14. THANK YOU --BY HUI PENGTAO

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