1kix

From Proteopedia

Dimeric Structure of the O. nova Telomere End Binding Protein Alpha Subunit with Bound ssDNA

PDB ID 1kix

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Structural highlights

1kix is a 2 chain structure with sequence from Sterkiella nova. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance.
Method:	X-ray diffraction, Resolution 2.7Å
Ligands:
Resources:	FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT

Function

TEBA_STENO May function as protective capping of the single-stranded telomeric overhang. May also participate in telomere length regulation during DNA replication. Binds specifically to the T4G4-containing extension on the 3'strand and protects this region of the telomere from nuclease digestion and chemical modification.

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 PubMed

Telomeres are the specialized protein--DNA complexes that cap and protect the ends of linear eukaryotic chromosomes. The extreme 3' end of the telomeric DNA in Oxytricha nova is bound by a two-subunit sequence-specific and 3' end-specific protein called the telomere end-binding protein (OnTEBP). Here we describe the crystal structure of the alpha-subunit of OnTEBP in complex with T4G4 single-stranded telomeric DNA. This structure shows an (alpha--ssDNA)2 homodimer with a large approximately 7,000 A2 protein--protein interface in which the domains of alpha are rearranged extensively from their positions in the structure of an alpha--beta--ssDNA ternary complex. The (alpha--ssDNA)2 complex can bind two telomeres on opposite sides of the dimer and, thus, acts as a protein mediator of telomere--telomere associations. The structures of the (alpha--ssDNA)2 dimer presented here and the previously described alpha--beta--ssDNA complex demonstrate that OnTEBP forms multiple telomeric complexes that potentially mediate the assembly and disassembly of higher order telomeric structures.

Dimeric structure of the Oxytricha nova telomere end-binding protein alpha-subunit bound to ssDNA.,Peersen OB, Ruggles JA, Schultz SC Nat Struct Biol. 2002 Mar;9(3):182-7. PMID:11836536^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

References

↑ Peersen OB, Ruggles JA, Schultz SC. Dimeric structure of the Oxytricha nova telomere end-binding protein alpha-subunit bound to ssDNA. Nat Struct Biol. 2002 Mar;9(3):182-7. PMID:11836536 doi:http://dx.doi.org/10.1038/nsb761