1exe | pdb_00001exe
SOLUTION STRUCTURE OF A MUTANT OF TRANSCRIPTION FACTOR 1.
Structural highlights
Function[TF1_BPSP1] Selectively binds to and inhibits the transcription of hydroxymethyluracil-(hmUra)-containing DNA, such as SP01 DNA, by RNA polymerase in vitro. Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedAn NMR solution structure of a mutant of the homodimer protein transcription factor 1, TF1-G15/I32 (22 kDa), has been solved to atomic resolution, with 23 final structures that converge to an r.m. s.d. of 0.78 A. The overall shape of TF1-G15/I32 remains similar to that of the wild-type protein and other type II DNA-binding proteins. Each monomer has two N-terminal alpha-helices separated by a short loop, followed by a three-stranded beta-sheet, whose extension between the second and third beta-strands forms an antiparallel beta-ribbon arm, leading to a C-terminal third alpha-helix that is severely kinked in the middle. Close examination of the structure of TF1-G15/I32 reveals why it is more stable and binds DNA more tightly than does its wild-type counterpart. The dimeric core, consisting of the N-terminal helices and the beta-sheets, is more tightly packed, and this might be responsible for its increased thermal stability. The DNA-binding domain, composed of the top face of the beta-sheet, the beta-ribbon arms and the C-terminal helices, is little changed from wild-type TF1. Rather, the enhancement in DNA affinity must be due almost exclusively to the creation of an additional DNA-binding site at the side of the dimer by changes affecting helices 1 and 2: helix 2 of TF1-G15/I32 is one residue longer than helix 2 of the wild-type protein, bends inward, and is both translationally and rotationally displaced relative to helix 1. This rearrangement creates a longer, narrower fissure between the V-shaped N-terminal helices and exposes additional positively charged surface at each side of the dimer. Solution structure of a mutant of transcription factor 1: implications for enhanced DNA binding.,Liu W, Vu HM, Geiduschek EP, Kearns DR J Mol Biol. 2000 Sep 29;302(4):821-30. PMID:10993726[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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