Summary information and primary citation
- PDB-id
-
1ph4;
SNAP-derived features in text and
JSON formats
- Class
- DNA binding protein-DNA
- Method
- X-ray (2.3 Å)
- Summary
- Crystal structure of the oxytricha nova telomere
end-binding protein complexed with noncognate ssDNA
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- Reference
-
Theobald DL, Schultz SC (2003): "Nucleotide
Shuffling and ssDNA Recognition in Oxytricha Nova
Telomere End-Binding Protein Complexes." Embo
J., 22, 4314-4324. doi: 10.1093/emboj/cdg415.
- Abstract
- Sequence-specific protein recognition of
single-stranded nucleic acids is critical for many
fundamental cellular processes, such as DNA replication,
DNA repair, transcription, translation, recombination,
apoptosis and telomere maintenance. To explore the
mechanisms of sequence-specific ssDNA recognition, we
determined the crystal structures of 10 different
non-cognate ssDNAs complexed with the Oxytricha nova
telomere end-binding protein (OnTEBP) and evaluated their
corresponding binding affinities (PDB ID codes 1PH1-1PH9
and 1PHJ). The thermodynamic and structural effects of
these sequence perturbations could not have been predicted
based solely upon the cognate structure. OnTEBP
accommodates non-cognate nucleotides by both subtle
adjustments and surprisingly large structural
rearrangements in the ssDNA. In two complexes containing
ssDNA intermediates that occur during telomere extension by
telomerase, entire nucleotides are expelled from the
complex. Concurrently, the sequence register of the ssDNA
shifts to re-establish a more cognate-like pattern. This
phenomenon, termed nucleotide shuffling, may be of general
importance in protein recognition of single-stranded
nucleic acids. This set of structural and thermodynamic
data highlights a fundamental difference between protein
recognition of ssDNA versus dsDNA.
