| ID | Symbol | Description | Aliases |
| YHR031C | RRM3 | DNA helicase involved in rDNA replication and Ty1 transposition; structurally and functionally related to Pif1p | RTT104 | |
| YBR136W | MEC1 | 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 | ESR1, SAD3 | |
| YLR103C | CDC45 | DNA replication initiation factor; recruited to MCM pre-RC complexes at replication origins; promotes release of MCM from Mcm10p, recruits elongation machinery; mutants in human homolog may cause velocardiofacial and DiGeorge syndromes | SLD4 | |
| YAR007C | RFA1 | Subunit of heterotrimeric Replication Factor A (RF-A), which is a highly conserved single-stranded DNA binding protein involved in DNA replication, repair, and recombination | BUF2, FUN3, RPA1 | |
| YHR164C | DNA2 | Essential tripartite DNA replication factor with single-stranded DNA-dependent ATPase, ATP-dependent nuclease, and helicase activities; required for Okazaki fragment processing; involved in DNA repair pathways; potential Cdc28p substrate | WEB2 | |
| YCL061C | MRC1 | S-phase checkpoint protein found at replication forks, required for DNA replication; also required for Rad53p activation during DNA replication stress, where it forms a replication-pausing complex with Tof1p and is phosphorylated by Mec1p; protein involved in replication checkpoint | YCL060C | |
| YDR217C | RAD9 | 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 | | |