Utilization of Site-Specific Recombination in Biopharmaceutical ...
27 and 29 September, 2006 Chapter 11 Transposition and Site- Specific Recombination.
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Transcript of 27 and 29 September, 2006 Chapter 11 Transposition and Site- Specific Recombination.
27 and 29 September, 2006
Chapter 11
Transposition and Site-Specific Recombination
Overview• Conservative Site-Specific Recombination (CSSR) may involve
insertion, deletion, or inversion of DNA sequences.• Site-specific recombinases have a mechanism that includes a DNA-
protein covalent intermediate.• CSSR may be regulated by the presence or absence of accessory
proteins.• Resolvases are CSSR recombinases that disentangle circular
chromosomes.• Transposons move using recombination pathways.• Transposons may be autonomous or nonautonomous.• DNA transposons and viral-like retrotransposons move via a cut/paste
mechanism.• Retrotransposon movement involves reverse transcription.• Some transposons regulate copy number or control target site selection
through the use of proteins or antisense RNA.• V(D)J recombination uses regulated, specific recombination to generate
immune diversity.
Recombination and Transposition
CSSR: Prophage Insertion
Three Classes of CSSR
Recombinase Recognition Sites
Recombinase Mechanism
Serine Recombinases
Tyrosine Recombinases
Mechanism of Cre
Recombinase
Cre-DNA Structure
Lambda integration
requires architectural
proteins.
Int and IHF stabilize bent
DNA.
Hin Inversion
Hin inversion requires Fis bound at an enhancer.
Resolvases disentangle circular DNAs after replication.
FtsK Regulation of
the Xer Resolvase
Mechanism
FtsK is present at the division closure site.
Conservative and Replicative Transposition
Transposons in Several Genomes
Types of Transposons
Cut and Paste Transposition
Three Mechanisms for Cleaving the Nontransferred Strand
Replicative Transposition
Retrotransposon Movement
Retrotransposon Movement
Retrotransposon Movement
DNA Transposases and retroviral integrases are members of the same protein superfamily.
LINE poly-A Retrotransposon
Movement
Tn10 achieves antisense copy control by overlapping promoters.
Antisense Copy
Control
Tn10 transposase promoter is active only
when hemimethylated.
MuA and MuB participate in selecting Mu transposition
target sequences.
MuA disrupts MuB assembly,
conferring transposition
target immunity.
Clustered Integration of Yeast Ty Elements
Antibody
V(D)J Recombination
Recombination Signal Sequences
V(D)J Recombination
Mechanism
Title
LINES and SINES Again?