5y58

Structural highlights

Function

KU70_YEAST Single-stranded DNA-dependent ATP-dependent helicase. Involved in non-homologous end joining (NHEJ) DNA double strand break repair. DNA-binding is sequence-independent but has a high affinity to nicks in double-stranded DNA and to the ends of duplex DNA. Binds to naturally occurring chromosomal ends, and therefore provides chromosomal end protection. Appears to have a role in recruitment of telomerase and CDC13 to the telomere and the subsequent telomere elongation. Required also for telomere recombination to repair telomeric ends in the absence of telomerase. KU70, of the KU70/KU80 heterodimer, binds to the stem loop of TLC1, the RNA component of telomerase. Involved in telomere maintenance. Interacts with telomeric repeats and subtelomeric sequences thereby controlling telomere length and protecting against subtelomeric rearrangement. Maintains telomeric chromatin, which is involved in silencing the expression of genes located at the telomere. Required for mating-type switching.^{[1] [2] [3] [4] [5] [6] [7] [8] [9] [10] [11]}

See Also

• Helicase 3D structures
• Ku protein

References

1. ↑ de la Torre-Ruiz M, Lowndes NF. The Saccharomyces cerevisiae DNA damage checkpoint is required for efficient repair of double strand breaks by non-homologous end joining. FEBS Lett. 2000 Feb 11;467(2-3):311-5. PMID:10675560
2. ↑ Grandin N, Damon C, Charbonneau M. Cdc13 cooperates with the yeast Ku proteins and Stn1 to regulate telomerase recruitment. Mol Cell Biol. 2000 Nov;20(22):8397-408. PMID:11046137
3. ↑ Tsai YL, Tseng SF, Chang SH, Lin CC, Teng SC. Involvement of replicative polymerases, Tel1p, Mec1p, Cdc13p, and the Ku complex in telomere-telomere recombination. Mol Cell Biol. 2002 Aug;22(16):5679-87. PMID:12138180
4. ↑ Stellwagen AE, Haimberger ZW, Veatch JR, Gottschling DE. Ku interacts with telomerase RNA to promote telomere addition at native and broken chromosome ends. Genes Dev. 2003 Oct 1;17(19):2384-95. Epub 2003 Sep 15. PMID:12975323 doi:http://dx.doi.org/10.1101/gad.1125903
5. ↑ Bertuch AA, Lundblad V. The Ku heterodimer performs separable activities at double-strand breaks and chromosome termini. Mol Cell Biol. 2003 Nov;23(22):8202-15. PMID:14585978
6. ↑ Mages GJ, Feldmann HM, Winnacker EL. Involvement of the Saccharomyces cerevisiae HDF1 gene in DNA double-strand break repair and recombination. J Biol Chem. 1996 Apr 5;271(14):7910-5. PMID:8626469
7. ↑ Tsukamoto Y, Kato J, Ikeda H. Hdf1, a yeast Ku-protein homologue, is involved in illegitimate recombination, but not in homologous recombination. Nucleic Acids Res. 1996 Jun 1;24(11):2067-72. PMID:8668537
8. ↑ Laroche T, Martin SG, Gotta M, Gorham HC, Pryde FE, Louis EJ, Gasser SM. Mutation of yeast Ku genes disrupts the subnuclear organization of telomeres. Curr Biol. 1998 May 21;8(11):653-6. PMID:9635192
9. ↑ Nugent CI, Bosco G, Ross LO, Evans SK, Salinger AP, Moore JK, Haber JE, Lundblad V. Telomere maintenance is dependent on activities required for end repair of double-strand breaks. Curr Biol. 1998 May 21;8(11):657-60. PMID:9635193
10. ↑ Polotnianka RM, Li J, Lustig AJ. The yeast Ku heterodimer is essential for protection of the telomere against nucleolytic and recombinational activities. Curr Biol. 1998 Jul 2;8(14):831-4. PMID:9663392
11. ↑ Evans SK, Sistrunk ML, Nugent CI, Lundblad V. Telomerase, Ku, and telomeric silencing in Saccharomyces cerevisiae. Chromosoma. 1998 Dec;107(6-7):352-8. PMID:9914366