Terms in this set (24)

DNA polymerase I -> DNA synthesis. 3' to 5' exonuclease (for proofreading); 5' to 3' exonuclease removes and replaces RNA primers used in DNA replication.

Primase -> RNA synthesis, makes RNA oligonucleotides that are used as primers for DNA synthesis.

DNA helicase ->Unwinds double-stranded DNA.

Single-stranded DNA binding protein (SSB) -> Binds to single stranded DNA, stablises strands of unwound DNA in an extended configuration that facilitates access by other proteins.

DNA topoisomerase I -> Makes single-strand cuts in DNA. induces and or relaxes supercoiling. Can serve as swivel to prevent overwinding ahead of the DNA replication fork. Can separate linked DNA circles at the end of replication.

DNA topoisomerase II -> Makes double-strand cuts in DNA. Activated by sites on chromosomes where two double helices cross over each other. Induces and or relaxes supercoiling. Can serve as swivel to prevent overwinding ahead of the DNA replication fork. Can separate linked DNA circles at the end of replication.

DNA gyrase - Type II DNA topoisomerase that serves as a swivel to relax supercoiling ahead of the replication fork in E. coli.

DNA ligase - Makes covalent bonds to join together adjacent DNA strands, including Okazaki fragments in lagging strand DNA synthesis, and the new and old DNA segments in excision repair of DNA.

Initiator proteins - Bind to origin of replication and initiate unwinding of DNA double helix.

Telomerase - Using an integral RNA molecule as template, synthesises DNA for extension of telomeres. (Sequences at ends of chromosomal DNA) (Telomeres and telomerases prevent linear eukaryotic chromosomes from shortening with each cell division)
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