Polymerases and Restriction Enzymes

α

(Eukaryotic) DNA Polymerase Alpha

α

Lagging strand synthesis during DNA replication

α

Found in Nucleus - Family B

β

(Eukaryotic) DNA Polymerase Beta

β

DNA Repair mechanisms, and Replication restart at nicks and lesions

β

Found in Nucleus Family X

δ

(Eukaryotic) DNA Polymerase Delta

δ

Primary DNA polymerase - synthesizes leading strand.

δ

Found in Nucleus - Family B

ε

(Eukaryotic) DNA Polymerase Epsilon

ε

mostly for repair but can substitute for Delta when needed.

ε

Found in Nucleus - Family B

γ

(Eukaryotic) DNA Polymerase Gamma

γ

mitochondrial replication only, responsible for replicating and repairing mitochondrial DNA (mtDNA)

γ

Found in Mitochondria - Family A

Pol I

(Prokaryotic) DNA Polymerase 1

Pol I

Lagging strand synthesis during DNA replication.

Pol I

15-20 nucleotides added per second onto the RNA primer

Pol II

DNA polymerase 2

Pol II

DNA Repair mechanisms, and Replication restart at nicks and lesions

Pol II

Can interact with POL III and holoenzymes

Pol III

DNA Polymerase 3

Pol III

Primary DNA polymerase-synthesizes leading strand

Pol III

Major contributor to holoenzyme activity.; 1000+ nucleotides per second

RNA Pol I

RNA Polymerase 1

RNA Pol I

Synthesizes rRNA

RNA Pol I

Needed for translation

RNA Pol II

RNA Polymerase 2

RNA Pol II

Synthesizes mRNA

RNA Pol II

Gene transcription

RNA Pol III

RNA Polymerase 3

RNA Pol III

Synthesizes tRNA and snRNA

RNA Pol III

Needed for Protein Translation

RE I

Type 1 Restriction Enzymes

RE I

nuclease and methylase activity - recognizes specific sites 4-6 bp separated by 6-8 bp and contains methylated adenines

RE I

cuts up to 1000 bp away from recognition site

RE II

Type 2 Restriction Enzymes

RE II

Recognition sites are palindromic and cut is at or near the recognition site

RE II

cut methods can differ leaving “sticky ends” or “blunt ends”

RE III

Type 3 Restriction Enzymes

RE III

Resemble Type one enzymes-recognize sites the are asymetrical

RE III

cuts 24-26 bp away from recognition site 3’ side

RE IV

Type 4 Restriction Enzymes

RE IV

Resemble Type One enzymes-recognize sites that are asymetrical

RE IV

cuts 10 bp away from recognition site 3’ side