1vf9
From Proteopedia
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Solution Structure Of Human Trf2
Overview
Mammalian telomeres consist of long tandem arrays of double-stranded, telomeric TTAGGG repeats packaged by the telomeric DNA-binding proteins, TRF1 and TRF2. Both contain a similar C-terminal Myb domain that mediates, sequence-specific binding to telomeric DNA. In a DNA complex of TRF1, only, the single Myb-like domain consisting of three helices can bind, specifically to double-stranded telomeric DNA. TRF2 also binds to, double-stranded telomeric DNA. Although the DNA binding mode of TRF2 is, likely identical to that of TRF1, TRF2 plays an important role in the, t-loop formation that protects the ends of telomeres. Here, to clarify the, details of the double-stranded telomeric DNA-binding modes of TRF1 and, TRF2, we determined the solution structure of the DNA-binding domain of, human TRF2 bound to telomeric DNA; it consists of three helices, and like, TRF1, the third helix recognizes TAGGG sequence in the major groove of DNA, with the N-terminal arm locating in the minor groove. However, small but, significant differences are observed; in contrast to the minor groove, recognition of TRF1, in which an arginine residue recognizes the TT, sequence, a lysine residue of TRF2 interacts with the TT part. We examined, the telomeric DNA-binding activities of both DNA-binding domains of TRF1, and TRF2 and found that TRF1 binds more strongly than TRF2. Based on the, structural differences of both domains, we created several mutants of the, DNA-binding domain of TRF2 with stronger binding activities compared to, the wild-type TRF2.
About this Structure
1VF9 is a Single protein structure of sequence from Homo sapiens. Full crystallographic information is available from OCA.
Reference
Comparison between TRF2 and TRF1 of their telomeric DNA-bound structures and DNA-binding activities., Hanaoka S, Nagadoi A, Nishimura Y, Protein Sci. 2005 Jan;14(1):119-30. PMID:15608118
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