Subunit of a complex with Rad50p and Xrs2p (MRX complex) that functions in repair of DNA double-strand breaks and in telomere stability, exhibits nuclease activity that appears to be required for MRX function; widely conserved; Involved in DNA double-strand break repair (DSBR). Possesses single-strand endonuclease activity and double-strand- specific 3’-5’ exonuclease activity. Also involved in meiotic DSB processing (692 aa)

Checkpoint protein, involved in the activation of the DNA damage and meiotic pachytene checkpoints; subunit of a clamp loader that loads Rad17p-Mec3p-Ddc1p onto DNA; homolog of human and S. pombe Rad17 protein; Participates in checkpoint pathways arrest of the cell cycle, a mechanism that allows the DNA repair pathways to act to restore the integrity of the DNA prior to DNA synthesis or separation of the replicated chromosomes. Regulates the DNA damage checkpoint pathway throughout the cell cycle, when associated with RCF5. Component of the RFC-like RAD24-RFC complex which loads the ch [...] (659 aa)

Genome integrity checkpoint protein and PI kinase superfamily member; signal transducer required for cell cycle arrest and transcriptional responses prompted by damaged or unreplicated DNA; monitors and participates in meiotic recombination; Serine/threonine protein kinase which activates checkpoint signaling upon genotoxic stresses such as ionizing radiation (IR), ultraviolet light (UV), or DNA replication stalling, thereby acting as a DNA damage sensor. Recognizes the substrate consensus sequence [ST]-Q. Recruited in complex with protein LCD1 by the single-strand-binding protein comp [...] (2368 aa)

DNA damage-dependent checkpoint protein, required for cell-cycle arrest in G1/S, intra-S, and G2/M; transmits checkpoint signal by activating Rad53p and Chk1p; hyperphosphorylated by Mec1p and Tel1p; potential Cdc28p substrate; Essential for cell cycle arrest at the G2 stage following DNA damage by X-irradiation or inactivation of DNA ligase (1309 aa)

Histone H2A, core histone protein required for chromatin assembly and chromosome function; one of two nearly identical subtypes (see also HTA2); DNA damage-dependent phosphorylation by Mec1p facilitates DNA repair; acetylated by Nat4p; Core component of nucleosome which plays a central role in DNA double strand break (DSB) repair. Nucleosomes wrap and compact DNA into chromatin, limiting DNA accessibility to the cellular machineries which require DNA as a template. Histones thereby play a central role in transcription regulation, DNA repair, DNA replication and chromosomal stability. D [...] (132 aa)

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; 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. Appe [...] (629 aa)

Protein kinase, required for cell-cycle arrest in response to DNA damage; activated by trans autophosphorylation when interacting with hyperphosphorylated Rad9p; also interacts with ARS1 and plays a role in initiation of DNA replication; Controls S-phase checkpoint as well as G1 and G2 DNA damage checkpoints. Phosphorylates proteins on serine, threonine, and tyrosine. Prevents entry into anaphase and mitotic exit after DNA damage via regulation of the Polo kinase CDC5. Seems to be involved in the phosphorylation of RPH1 (821 aa)

Cell-cycle checkpoint serine-threonine kinase required for DNA damage-induced transcription of certain target genes, phosphorylation of Rad55p and Sml1p, and transient G2/M arrest after DNA damage; also regulates postreplicative DNA repair; Transducer of the DNA damage signal. Phosphorylates SML1 on serine residues. Cooperates with the PAN deadenylation complex in the regulation of RAD5 mRNA levels and cell survival in response to replicational stress (513 aa)