CRISPR Technology Lecture Notes

Key vocabulary and concepts related to CRISPR technology.

CRISPR

Clusters of Regularly Interspaced Short Palindromic Repeats; repetitive DNA sequences in bacteria genomes.

CRISPR-associated (Cas) genes

Genes located near CRISPR arrays that encode proteins part of the adaptive immune system in bacteria.

Adaptive Immune System (in bacteria)

Acquired sequences integrated into CRISPR arrays that become templates for RNA molecules.

Palindromic Repeats

Sequences in CRISPR arrays that can fold back and form hairpin structures recognized by CRISPR Cas proteins.

Surveillance Complexes

Complexes formed by CRISPR RNAs combining with Cas proteins to search for matching DNA or RNA sequences.

Class 1 CRISPR systems

CRISPR systems that include multiple Cas proteins that assemble with CRISPR RNAs to form surveillance complexes.

Class 2 CRISPR systems

CRISPR systems that include a single gene encoding one large protein that combines with CRISPR RNAs for protection.

Cas9

An enzyme that recognizes double-stranded DNA at positions matching a 20 nucleotide sequence in a guiding RNA.

Guide RNA

An RNA molecule that directs Cas9 to a specific DNA sequence for cutting.

Tracer RNA

A second RNA that combines with guide RNA to form a structure that binds to Cas9.(Can be engineered)

HNH domain

The part of the Cas9 protein that cuts the DNA strand that base pairs with the guide RNA.

Non-target Strand

The strand of DNA that is not directly targeted by the guide RNA in Cas9 mediated DNA cleavage.

Resonance Energy Transfer (FRET)

A technique used to detect structural changes in proteins by monitoring changes in distances between atoms or amino acids.

Anti-CRISPR proteins

Proteins encoded by host organisms that inhibit CRISPR systems.

C1

An example of anti CRISPR that can block DNA cutting.

Responsible Progress

Proceeding with caution and respect for the powerful CRISPR technology.

CRISPR arrays

Distinctive features in the chromosome of bacteria that include repetitive sequences

Anti CRISPR Mechanism

Anti CRISPR protein grabs onto the HNH domain in Cas9, preventing it from swinging into place and cutting the DNA.

DNA conformational states

Cas 9 has the ability to change conformation upon binding to nucleic acid

DNA repair machinery

Cells have sophisticated machinery to repair double stranded breaks; They can do so by introducing a small change at the side of the break or even by integrating a new piece of DNA during the process of repair.