Lecture 17 Flashcards
CRISPR “spacer” sequences are transcribed into short RNA sequences (crRNAs) capable of…
guiding the system to matching the sequences of DNA
what happens when the target DNA is found?
Cas9 binds to the DNA and cuts it
what are the 2 types of RNAs that allow Cas9 binding and cutting?
crRNA, tracrRNA
crRNA is made from blank and is specific to blank
the CRISPR locus; the invading DNA virus
crRNA guides the Cas9 protein to the…
target sequence
tracrRNA
trans-activating crRNA
tracrRNA is partially complementary to the crRNA and base pairs with the…
crRNA
tracrRNA allows the formation of the…
Cas9-CRISPR complex
what does PAM stand for?
protospacer adjacent motif
the PAM is the DNA sequence immediately following the…
DNA sequences targeted by Cas9
PAM is a component of the…
invading virus or plasmid
PAM is NOT a component of the…
bacterial CRISPR locus
Cas9 will not successfully bind to or cleave the target DNA sequence if it is not followed by…
the PAM sequence 5’-NGG-3’
Cas9 cuts blank bps upstream of the PAM sequence
3-5 bps
we can fuse the tracrRNA and the crRNA into a single RNA called the…
guide RNA (gRNA)
we can modify the regions of the gRNA to target…
specific sequences
we need to target specific sequences that will adhere to these 2 CRISPR rules…
1) target site must be 20 bps
2) there must be a PAM site
