Chymotrypsin

Proteases

Class Nucleophile(s) BaseCovalent Intermediate

Serine protease

Cysteine protease

Aspartyl protease

Metalloprotease (Zn)

Ser/water

Cys/water

water

water

His

His

Asp

Glu

Yes

Yes

No

No

Proton Shuttle in Carbonic Anhydrase

RNA Secondary and Tertiary Structure

Hepatitis Delta Virus Ribozyme

Hydrolysis of a phosphodiester bond by a Ribozyme

Clone and test forRibozyme that Hydrolyzes ATP

(RT-PCR)

Genetic diversity

More genetic diversity!

in vitro Evolution of a Ribozyme

(affinity chromatography)