1ph6
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Crystal Structure of THE OXYTRICHA NOVA TELOMERE END-BINDING PROTEIN COMPLEXED WITH NONCOGNATE SSDNA GGGGTTTTGTGG
OverviewOverview
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.
About this StructureAbout this Structure
1PH6 is a Protein complex structure of sequences from Sterkiella nova with NA as ligand. Full crystallographic information is available from OCA.
ReferenceReference
Nucleotide shuffling and ssDNA recognition in Oxytricha nova telomere end-binding protein complexes., Theobald DL, Schultz SC, EMBO J. 2003 Aug 15;22(16):4314-24. PMID:12912928
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