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Protein FULL name:

Subunit of the telomeric Ku complex (Yku70p-Yku80p), involved in telomere length maintenance, structure and telomere position effect; relocates to sites of double-strand cleavage to promote nonhomologous end joining during DSB repair (YKU80)

Yku80p (Saccharomyces cerevisiae) is product of expression of YKU80 gene.

Yku80p is involved in:

NHEJ in Saccharomyces cerevisiae


FUNCTION: 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.

CATALYTIC ACTIVITY: ATP + H(2)O = ADP + phosphate.

SUBUNIT: Heterodimer of YKU70/HDF1 and YKU80/HDF2. Interacts with SIR4.

INTERACTION: P11978:SIR4; NbExp=1; IntAct=EBI-8224, EBI-17237; P32807:YKU70; NbExp=1; IntAct=EBI-8224, EBI-8214;


MISCELLANEOUS: Present with 358 molecules/cell in log phase SD medium.

SIMILARITY: Belongs to the ku80 family.

SIMILARITY: Contains 1 Ku domain.

NCBI GenPept GI number(s): 296147223
Species: Saccharomyces cerevisiae

Links to other databases:

Database ID Link
Uniprot Q04437 Q04437
PFAM: - Q04437 (Link - using uniprot id)
InterPro: - Q04437 (Link - using uniprot id)
CATH: - -
SCOP: - -
PDB: - -

Protein sequence:


Title Authors Journal
A putative homologue of the human autoantigen Ku from Saccharomyces cerevisiae. Feldmann H, Winnacker EL J Biol Chem June 15, 1993
HDF2, the second subunit of the Ku homologue from Saccharomyces cerevisiae. Feldmann H, Driller L, Meier B, Mages G, Kellermann J, Winnacker EL J Biol Chem Nov. 1, 1996
Identification of a Saccharomyces cerevisiae Ku80 homologue: roles in DNA double strand break rejoining and in telomeric maintenance. Boulton SJ, Jackson SP Nucleic Acids Res Dec. 1, 1996
The nucleotide sequence of Saccharomyces cerevisiae chromosome XIII. Bowman S, Churcher C, Badcock K, Brown D, Chillingworth T, Connor R, Dedman K, Devlin K, Gentles S, Hamlin N, Hunt S, Jagels K, Lye G, Moule S, Odell C, Pearson D, Rajandream M, Rice P, Skelton J, Walsh S, Whitehead S, Barrell B Nature May 1, 1997
Yeast Ku as a regulator of chromosomal DNA end structure. Gravel S, Larrivee M, Labrecque P, Wellinger RJ Science May 1, 1998
Mutation of yeast Ku genes disrupts the subnuclear organization of telomeres. Laroche T, Martin SG, Gotta M, Gorham HC, Pryde FE, Louis EJ, Gasser SM Curr Biol May 21, 1998
Telomere maintenance is dependent on activities required for end repair of double-strand breaks. Nugent CI, Bosco G, Ross LO, Evans SK, Salinger AP, Moore JK, Haber JE, Lundblad V Curr Biol May 21, 1998
The yeast Ku heterodimer is essential for protection of the telomere against nucleolytic and recombinational activities. Polotnianka RM, Li J, Lustig AJ Curr Biol July 2, 1998
Telomerase, Ku, and telomeric silencing in Saccharomyces cerevisiae. Evans SK, Sistrunk ML, Nugent CI, Lundblad V Chromosoma Dec. 1, 1998
The Saccharomyces cerevisiae DNA damage checkpoint is required for efficient repair of double strand breaks by non-homologous end joining. de la Torre-Ruiz M, Lowndes NF FEBS Lett Jan. 11, 2000
Cdc13 cooperates with the yeast Ku proteins and Stn1 to regulate telomerase recruitment. Grandin N, Damon C, Charbonneau M Mol Cell Biol Nov. 1, 2000
Involvement of replicative polymerases, Tel1p, Mec1p, Cdc13p, and the Ku complex in telomere-telomere recombination. Tsai YL, Tseng SF, Chang SH, Lin CC, Teng SC Mol Cell Biol Aug. 1, 2002
Ku interacts with telomerase RNA to promote telomere addition at native and broken chromosome ends. Stellwagen AE, Haimberger ZW, Veatch JR, Gottschling DE Genes Dev Oct. 1, 2003
Global analysis of protein expression in yeast. Ghaemmaghami S, Huh WK, Bower K, Howson RW, Belle A, Dephoure N, O'Shea EK, Weissman JS Nature Oct. 16, 2003
The Ku heterodimer performs separable activities at double-strand breaks and chromosome termini. Bertuch AA, Lundblad V Mol Cell Biol Nov. 1, 2003
Separation-of-function mutants of yeast Ku80 reveal a Yku80p-Sir4p interaction involved in telomeric silencing. Roy R, Meier B, McAinsh AD, Feldmann HM, Jackson SP J Biol Chem Feb. 2, 2004
The DNA repair protein yKu80 regulates the function of recombination enhancer during yeast mating type switching. Ruan C, Workman JL, Simpson RT Mol Cell Biol Oct. 1, 2005
Sequence diversity, reproductive isolation and species concepts in Saccharomyces. Liti G, Barton DB, Louis EJ Genetics Oct. 1, 2006

Last modification of this entry: Oct. 15, 2010.

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