PRESENTATION II NAME By Christine Harvey Dihydrofolate Reductase Beta lactmase p300 Macrophage Infectivity Potentiator
Dec 28, 2015
PRESENTATION II NAME
By Christine Harvey
Dihydrofolate Reductase Beta lactmasep300Macrophage Infectivity Potentiator
Dihydrofolate Reductase
in Escherichia coli
http://en.wikipedia.org/wiki/DHFR
• Class: oxidoreductase
• Reduces dihydrofolate (DHF) to tetrahydrofolate (THF)
• THF is a precursor to amino acids, purine and thymidylate.
• DHFR is imperative to cell life
Function
Source: Schweitzer, Barry I., et al. The FASEB Journal Vol 4, “Dihydrofolate reductase as a therapeutic target.” May 1990.
Mechanism
http://en.wikipedia.org/wiki/DHFR
Structure
Binding Pocket
Sequence Alignment
Phylogenetic Tree
Beta-Lactamasein Escherichia coli
• Class: Hydrolase
• Beta Lactamase is produce by bacteria after being exposed to beta lactam antibiotics
• Responsible for beta lactam antibiotic resistance
Penicillin
• Contains beta lactam ring
Mechanism
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p300In Homo Sapiens
• Class: Transferase
• p300 transfers an acetyl group from acetyl coenzyme A to an active site lysine
• Transcriptional activation occurs upon acetyl transfer
Title
• p300 is responsible for cell growth before and after birth
• Cancer suppressor
Domains
Taz2
KIX
Bromodomain
HAT
Zinc Fingers (3)
Taz2
Creb
Histone Acetyl Transferase
• Active site tyrosine acts as nucleophile
Source: http://www.bmolchem.wisc.edu/labs/denu/images/hats/sequential.jpg
Docking
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Macrophage Infectivity Potentiator
in Legionella pneumophila
Legionella pneumophila
• gram negative bacteria
• Causes Legionnaires’ disease
• Carried in aerosols from man-made water systems
MIP
• Class: Isomerase
• Catalyzes the isomeration of the N-terminal on proline
• Cause of virulence in Legionnaires’ disease
• Located on outer membrane protein
• 25 kDa
Crystalization
• Solution: 100 mM MES (pH 6.1–6.5), 15–20% (w/v) PEG 8000 and 500 mM zinc acetate. Protein concentration was 10 mg ml–1in 20 mM HEPES, pH 7.0
• Crystals were grown for 2-3 weeks at 288K
• X-ray data was collected at 100K in a nitrogen gas stream (dried paraffin oil) at 2.4 Angstrom resolution
• Multiwavelength anomalous dispersion (MAD) with zinc was used for phasing
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Source: Riboldi-Tunnicliffe, Alan et al., Nature Structural Biology, vol.8: 9. “Crystal structure of Mip, a prolylisomerase from Legionella pneumophila.” September 2001.
Mechanism
• Peptidyl-prolyl cis-trans isomerases’ (PPIases) mechanism is not currently know
Source: Park, Steven T., et al. Journal of Biological Chemistry. Vol. 267 No.5, “PPIase Catalysis by Human Fk506-binding Protein Proceeds Through a Conformational Twist Mechanism.” February 1992.
Source: Riboldi-Tunnicliffe, Alan et al., Nature Structural Biology, vol.8: 9. “Crystal structure of Mip, a prolylisomerase from Legionella pneumophila.” September 2001.
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Questions?