1kix: Difference between revisions

[[Image:1kix.gif|left|200px]]<br /><applet load="1kix" size="350" color="white" frame="true" align="right" spinBox="true"  

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.

1KIX is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Sterkiella_nova Sterkiella nova] with <scene name='pdbligand=SO4:'>SO4</scene> as [http://en.wikipedia.org/wiki/ligand ligand]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1KIX OCA].  

[[Category: Peersen, O B.]]

[[Category: Ruggles, J A.]]

[[Category: Schultz, S C.]]

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