Microbes in Synthetic Biology 2: Directed Evolution

Flashcards about Microbes in Synthetic Biology 2: Directed Evolution

Evolution

Change in the heritable characteristics of biological populations over successive generations.

Motility in Life

A crucial virulence factor as many organisms can move, allowing exploration of new hosts, habitats and niches.

Flagella

An organelle involved in motility in many bacterial and archaeal species.

Directed Evolution

A method used in protein engineering that mimics the process of natural selection to evolve proteins or nucleic acids toward a user-defined goal.

Experimental Evolution

The use of laboratory or controlled field manipulations to investigate evolutionary processes; designing experiments to study the molecular processes of evolution.

Basis of Evolution

Mutation and Selection

Frances Arnold's Nobel Prize Work

The directed evolution of enzymes.

George Smith and Gregory Winter Nobel Prize Work

The Phage Display of peptides and antibodies

Paleogenomics in modern day humans with European or Asian descent

Approximately 1-4% of the genome originates from the Neanderthals.

Phage Display

Presents a genetic information outside a cell as a peptide that we can then use for screening.

Methods to Introduce Mutations

Error-prone PCR, buying scrambled DNA, and using mutator strains.

How to Select Mutants

Manually, Semi-manually (robotics/plates), and automatically

Error Prone PCR

Can get up to 10% mutation rate per position and tune the ‘amount of mutation’

How to make Taq ‘bad’

Increase Mg2+, Add Mn2+, Unbalanced dNTP concentration

XL1-Red (Stratagene)

Mutations in their DNA repair pathways, Results in 5000-fold increase in spontaneous mutations.

Selection

Engineer biology to do the selection: Link protein function to growth or death.