15453464
Description
Flashcards by Sophie Byrne, updated more than 1 year ago
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Created by Sophie Byrne
about 6 years ago
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| Question | Answer |
| What do sortases do? | Surface display and cell wall anchoring of pili proteins Cleave sorting signal (protein) Joined to peptidoglycan precursors Incorporated into cell wall Protein (signal) stays attached to sortase |
| Describe the 3 adhesion steps (G +ve pilus) | 1. Pili interact w/ host cells' extracellular matrix 2. Zippering - bacterium pulled closer to cell surface 3. Pilus-mediated bacterial aggregation (more and more bacteria clump together forming microcolonies as interactions form b/w their cell surfaces |
| Describe the Gram negative pilus and its role, and give an example | Small tubular filaments (helical proteins) Role: adhesion, aggregation, biofilm formation e.g. Type IV pilus |
| Describe Neisseria gonorrhoeae's pilus activity | No zippering T4 pilus (main anchorage) and opa bind to host receptors Single interaction - pili retract; bacterium brought closer to host cell surface |
| What is opa? | Opacity-associated proteins |
| Describe twitching motility and give an example of an organism it is seen in | Neisseria gonorrhoeae 1. Pilus extends (catalysed by assembly ATPase) 2. Pilus attaches to host epithelium 3. Pilus retracts (retraction ATPase involved) 4. Moves 1 micrometre/sec |
| Describe the T3SS. Give an e.g. of a species it's seen in | EPEC 1. Channel forms b/w bacterial and host cell cytoplasm 2. Effectors (e.g. tir) inserted into host cell membrane 3. Intimin binds to tir; adhesion occurs 4. Other effectors interact w/ host cytoskeleton proteins and disassemble microvilli structure 5. Cytoskeleton reassembled into pedestal structure |
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