Structural highlights
Function
[TEBB_OXYNO] 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. [TEBA_OXYNO] 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
The Oxytricha nova telomere end binding protein (OnTEBP) recognizes, binds and protects the single-stranded 3'-terminal DNA extension found at the ends of macronuclear chromosomes. The structure of this complex shows that the single strand GGGGTTTTGGGG DNA binds in a deep cleft between the two protein subunits of OnTEBP, adopting a non-helical and irregular conformation. In extending the resolution limit of this structure to 1.86 A, we were surprised to find a G-quartet linked dimer of the GGGGTTTTGGGG DNA also packing within the crystal lattice and interacting with the telomere end binding protein. The G-quartet DNA exhibits the same structure and topology as previously observed in solution by NMR with diagonally crossing d(TTTT) loops at either end of the four-stranded helix. Additionally, the crystal structure reveals clearly visible Na(+), and specific patterns of bound water molecules in the four non-equivalent grooves. Although the G-quartet:protein contact surfaces are modest and might simply represent crystal packing interactions, it is interesting to speculate that the two types of telomeric DNA-protein interactions observed here might both be important in telomere biology.
DNA G-quartets in a 1.86 A resolution structure of an Oxytricha nova telomeric protein-DNA complex.,Horvath MP, Schultz SC J Mol Biol. 2001 Jul 6;310(2):367-77. PMID:11428895[1]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
References
- ↑ Horvath MP, Schultz SC. DNA G-quartets in a 1.86 A resolution structure of an Oxytricha nova telomeric protein-DNA complex. J Mol Biol. 2001 Jul 6;310(2):367-77. PMID:11428895 doi:10.1006/jmbi.2001.4766
