Molecular Biology

DNA Polymerase

Catalyze DNA replication in the 5’ to 3’ direction

DNA-dependent RNA Polymerase

Copy a template strand of DNA into RNA

RNA-dependent RNA Polymerase

 Copy a template strand of RNA into RNA

DNA Ligase

 Catalyzes formation of phosphodiester bonds between nucleotides 

Endonuclease

Cleave the sugar-phosphate bonds within a strand of DNA, generating

either blunt ends or a 5’ and 3’ overhang

Exonuclease

 Removes nucleotides from ends of single stranded DNA

Reverse-Transcriptase

RNA-dependent DNA polymerase

 Uses a hairpin formation on the end of the newly synthesized DNA strand to

prime synthesis of the complimentary DNA strand.

Primers

Short sequences of DNA that will hybridize to a target and direct

polymerases to the target sequence to be copied by the polymerase.  Primer pairs should have similar melting temperatures

 Tm too high: __________________________________________  Tm too low: ___________________________________________

Probes

A segment of nucleic acid, complementary to the target sequence, with a

covalently attached reporter molecule

Annealing

the mixture is allowed to cool so that

the primer will anneal to the target DNA in a

sequence-specific manner

Southern, Northern, Western

Blotting:

___ = DNA

___ = RNA

___ = Proteins