Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
DNA repair protein XRCC4 wikipedia , lookup
Homologous recombination wikipedia , lookup
DNA replication wikipedia , lookup
DNA profiling wikipedia , lookup
DNA polymerase wikipedia , lookup
United Kingdom National DNA Database wikipedia , lookup
DNA nanotechnology wikipedia , lookup
Microsatellite wikipedia , lookup
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 2 Zinc fingers * Positioned in the major groove and across the minor groove of DNA * Span the entire length of the duplex * Show how 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 3 Zinc fingers 2007221107100008 03.pse 2007221107100008 02.pse 4 TFIIIA complex (transcription factor IIIA complex ) The tripartite promoter containing * box A * intermediate element (IE) * box C sequences 5 Description of TFIIIA Structure * 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) 6 Six-fingers Different configuration 2007221107100008 01.pse 7 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. 8 Six-fingers Crystallographic assignment of zinc fingers and DNA bases to locations within the complex 9 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 10 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 11 Zinc Finger–DNA Interactions DNA majorgroove contacts with each of the zinc fingers 1, 2, 3, and 5 12 TFIIIA–DNA complex The structure of the TFIIIA–DNA complex shows how zinc fingers have been deployed to bind to separated promoter elements 13 --BY HUI PENGTAO 14