1yuj
From Proteopedia
SOLUTION NMR STRUCTURE OF THE GAGA FACTOR/DNA COMPLEX, 50 STRUCTURES
Structural highlights
Function[GAGA_DROME] Transcriptional activator that functions by regulating chromatin structure. Overcomes the repressive effects of chromatin by promoting the open chromatin conformation in promoter gene regions, thereby allowing access to other transcription factors. Binds to DNA Polycomb response elements (PREs) at the bithorax complex and to the proximal region of the engrailed promoter, and positively regulates transcription of many genes including homeotic ones. Binds to the DNA sequence (GA)n, with optimal binding to the pentamer 5'-GAGAG-3'. Binds DNA as an oligomer. May also act as a transcriptional repressor, maintaining the repressed state of genes including lolal, and down-regulating its own transcription. Required for dosage compensation in males and may be involved in oogenesis. Also has a role in nuclear division.[1] [2] [3] [4] [5] [6] [7] [8] Publication Abstract from PubMedThe structure of a complex between the DNA binding domain of the GAGA factor (GAGA-DBD) and an oligonucleotide containing its GAGAG consensus binding site has been determined by nuclear magnetic resonance spectroscopy. The GAGA-DBD comprises a single classical Cys2-His2 zinc finger core, and an N-terminal extension containing two highly basic regions, BR1 and BR2. The zinc finger core binds in the major groove and recognizes the first three GAG bases of the consensus in a manner similar to that seen in other classical zinc finger-DNA complexes. Unlike the latter, which require tandem zinc finger repeats with a minimum of two units for high affinity binding, the GAGA-DBD makes use of only a single finger complemented by BR1 and BR2. BR2 forms a helix that interacts in the major groove recognizing the last G of the consensus, while BR1 wraps around the DNA in the minor groove and recognizes the A in the fourth position of the consensus. The implications of the structure of the GAGA-DBD-DNA complex for chromatin remodelling are discussed. The solution structure of a specific GAGA factor-DNA complex reveals a modular binding mode.,Omichinski JG, Pedone PV, Felsenfeld G, Gronenborn AM, Clore GM Nat Struct Biol. 1997 Feb;4(2):122-32. PMID:9033593[9] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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