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85 Cards in this Set
- Front
- Back
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OriC
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specific DNA sequence where replication begins.
Move toward the poles during segregation. |
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DnaA
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binds to OriC and recruits DNA polymerase to initiate replication
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TerC
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DNA seq that signcals for DNA polymerase to stop replication. Contain Dif site.
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Tus
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A protein that binds to ter site and prevent replication by stopping DNAP at dif site.
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XerC/XerD
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Binds to Dif site and recruits DNA topoisomerse IV.
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Topoisomerase IV
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cuts one chromosome at the dif site, separate, and repaire the chromosome.
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What are some causes of mutations
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Errors during replication: mismatch, and slipped strand mispairing
Mutagens: chemical, UV, radiation |
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DNA polymerase III
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3 --> 5 proof-reading
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Methyl-directed mismatch repair
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MusS, MutL, MutH - excise damaged DNA and DNAP I repaire it.
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MusS
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recognize and binds to DNA distortion
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MutL
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linker protin recruits MusH to MusS
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MutH
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endonuclease nick DNA near damaged base
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DNA methyltransferase
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methylates DNA after replication
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How to activate SOS response
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RecA is activated when it binds to damaged base. It then causes cleavage of LexA and activate SOS genes.
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Rec A
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binds to damaged base.
After activation, cleave LexA |
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LexA
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Transcriptional repressor of SOS genes
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What does SOS genes do?
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SulA - inhibit FitZ and stop cell division
UvrABC - excise damaged NTD and repair DNAP IV - copies over damaged nucleotides |
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SulA
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Binds to FtsZ and block Z-ring formation. Inhibit cell division.
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UvrABC
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cleaves damaged NTD and allow DNAP to fix it. DNA excision repair
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DNAP IV
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error prone. Replicate past damaged bp
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Restriction enzyme
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recognize specific patterns on dsDNA and cut it into pieces. Ex. EcoRI
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DNA methyltransferase
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methylate DNA to protect itself from restriction system.
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Recombination
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Incoming DNA basepair with old sequence. Facilitated by RecA
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RecA
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facilitates strand invasion during recombination
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Transformation
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uptate of free DNA from environment by "com machinery"
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Conjugation
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export of DNA from one cell to another by "tra machinery"
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Transduction
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transfer genetc material by bacteriophage. Generalized & specialized.
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"com" competence machinery
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similar to Type IV pilus. Called naturally competent. Recombination after entering cytoplasm
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Conjugation
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transfer plasmid w/ sex pilus. tra machinery
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F factor
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fertility factor. Encodes sex pilus, tra machinery. plasmid w/ independent origin of replication.
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Conjugation process.
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Sex pilus pull cells into contanct. Use Tra machinery to transfer replicated plasmid.
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High Frequency recombination (Hfr)
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F factor spontaneously integrates into chromosome to create Hfr strain. Some parts of normal chromosome will be copied and trransfered during mating --> does not make a new donor strain.
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General transduction
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non-lytic transducing particle during phage infection -> transfer to another bacteria.
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Att site (attachment site)
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the DNA sequence at which phage is integrated.
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cI proteins
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represses phage gene expression
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SOS response
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cleaves phage repressor cI and activate phage lyhsis cycle.
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Specialized transduction
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come from the part of chromosome adjacent to prophage integration site.
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Chemotaxis
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directed mvmt w/ respect to a chemical gradient.
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Pfeffer
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capillary tube assay
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CCW
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run
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CW
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tumble
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Excitation
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Chemoattractants bind to MCP, inhibit CheA actiity --> unphosphorylation of CheY... cell runs.
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adaptation
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inhibition of behavioral response in presence of constant stimulus
CheR methyltransferase methylates to MCP. CheA is un-inhibited, CheY is phosphorylated, tumble starts |
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Histidine PRotein Kinase (HPK)
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Phosphorylates CheA to phosphorylate CheY to CheYP.
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CheYP
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binds to flagellar motor an dinstruct it to turn CW
Does not bind to DNA> |
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Methyl-accepting Chemotaxis Protein
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binds to CheA and partially inhibit CheA activity. Partial phosphorylation of CheY... biased random mvmt.
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Biofilm
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held together by extracellular polysaccharides.
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Cyclic-di GMP
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make to GTP to undergo Cxl.Inhibit motility of bacteria and induce formation of CPS
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EPS
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capsule or slime layer.
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Gene regulation of biofilm
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Depends on space and time
1. sporulation 2. matrix 3. motility. |
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ID50
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Infection dose. Number of bacteria that results in infection in 50% of host
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LD50
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Lethal dose. # of bacteria that kills 50% of host.
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Lysosome
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destroy Peptidoglycans. In tears.
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Iron secretion
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lactoferrin sequester iron and starve bacteria
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Macrophage
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secrete peroxide. Consume bacteria
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o-antigen
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unique sugar pattern on LPS
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H-antigen
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flaggelin
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K-antigen
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Capsule
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Adhesion
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bind to sugar patterns on host cells
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Capsule
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Sticky - attach to host
Protect from H2O2, antibodies, engulfment Form biofilms. |
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Avery transformation
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DNA is genetic material. Dead capsule strain w/ live capsulless strain --> virulent.
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Sidophores
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high iron affinity... can steal from lactoferrin.
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Exotoxin
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secreted toxic enzyme
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Endotoxin.
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Released from dead cell (LPS)
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hemolysins
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Exotoxin... create holes in host memebrane. Cuase it to burst.
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IgA protease
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degrade antibodies and prevent them from targeting bacteria
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A/B toxins
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A = toxin; B = delivery A in to host
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ADP-robosyltransferase
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Cholera A/B toxin. Breaks down NAD to ADPR and modify into GTP binding protein. GTP's induction of adenylate cyclase can no longer be turned off. Massive ion delivery to outside.
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Shiga Toxin
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From E. Coli O157:H7.
DEstroy euk ribosome |
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Which part on LPS is the endotoxin?
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Lipid A is the toxic part.
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Lipid A binding proteins
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bind to Lipid A fragments,and activate TLR4...cytokine cascade.Cause toxic shock syndrome
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Toxic shock syndrome
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dialation of all blood vessels
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Phospholipase
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Escape from endoglytic vesicles and grow in macromolecules (host)
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MIC
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miimal inhibition concentration. For antibodies.
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Where does 75% of antibodies come from?
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streptomyces
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Polyketide
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Huge molecule synthesis with giant synthase genes in a series.. can change order to modify protein.
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Polyketide regulation
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regulators are upstream
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Polyketide resistance
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resistance genes downstream.
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TetA tetracyclin exporter
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pump the antibiotic out.
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Immunity
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spontaneous mutation sin target.
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MMR
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measel mump rubella
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DTP
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diptheria, tetanus, pertusis
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Archaea
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psudopeptidoglycan, S-layer protein cell, ether linked lipids with branching, CdvABC
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Psudopeptiddoglycan
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No NAM.
Use N-acetyltalosamuric aid Use L AA instead of D aa for CxL |
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Archaea cell division
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CdvA, CdvB, CdvC.
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