Polymerases/Restriction Enzymes (MB ASCP)

α

(Eukaryotic) DNA Polymerase Alpha

Lagging strand synthesis during DNA replication.

Found in Nucleus- Family B

β

(Eukaryotic) DNA Polymerase Beta

DNA Repair mechanisms, and Replication restart at nicks and lesions

Found in Nucleus Family X

δ

(Eukaryotic) DNA Polymerase Delta

Primary DNA polymerase- synthesizes leading strand.

Found in Nucleus- Family B

ε

(Eukaryotic) DNA Polymerase Epsilon

mostly for repair but can substitute for Delta when needed.

Found in Nucleus- Family B

γ

(Eukaryotic) DNA Polymerase Gamma

mitochondrial replication only

Found in Mitochondria- Family A

Pol I

(prokarytotic) DNA Polymerase 1

Lagging strand synthesis during DNA replication.

15-20 nucleotides added per second onto the RNA Primer

Pol II

DNA Polymerase 2

DNA Repair mechanisms, and Replication restart at nicks and lesions

Can interact with POL III and holoenzymes.

Pol III

DNA Polymerase 3

Primary DNA polymerase- synthesizes leading strand. major contributor to holoenzyme activity.

1000+ nucleotides per second

RNA Pol I

Sythesizes rRNA

needed for translation

RNA Pol II

Synthesizes mRNA

Gene transcription

RNA Pol III

Synthesizes tRNA, and snRNA

Needed for protein translation

RE I

Type 1 Restriction Enzymes

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

cuts up to 1000 bp away from recognition site.

RE II

Type 2 Restriction Enzymes

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

cut methods can differ leaving "sticky Ends" or "blunt ends"

RE III

Type 3 Restriction Enzymes

Resemble Type one enzymes-recognize sites that are asymmetrical

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

RE IV

Type 4 Restriction Enzymes

Resemble Type one enzymes-recognize sites that are asymetrical

cuts 10 bp away from recognition site 3' side