Bacterial Flagella Function And Assembly Flashcards
How is flagella movement powered
Ion powered rotary motor embedded in bacterial cell surface
What does monotrichous mean
Single flagellum
E.g helibacter
What does Iophotrichous mean
Two or more flagella at one end
E.g vibrio fischeri
What does amphitchous mean
Single flagellum at both ends
E.g campylobacter jejuni
What are the three main structures to flagella
Basal body
Hook
Filament
What’s the rotary motor made up of
MS ring, rod, hook, filament
Component in gram negatives not present in gram positives
L and P rings
Only MS ring present in gram Positives
What are the function of Mot proteins
MotA is conduit for protons
MotB attaches cell membrane to peptidoglycan
Both are static
What makes up flagellum switch
FLiGMN proteins (in C ring)
What is the hook regions properties and what’s it made up of
- flexible
- axial hole
- approx 120 copies of FLgE protein
What the hook length control mechanism
Infrequent ruler mechanism
FliK is secreted and passes through axial hole and reacts with N terminus of FlgD/E and at the end it folds to pull the rest up, whereas if at maximum length due to more interacting in axial hole it cannot fold and has reached its full length so C terminus interacts with FlhB and induces its secretion.
What’s the filaments properties and what is it made of
20000 flagellin (FliC)
- self assemble into helical held together by interactions
- diameter = 20nm
- axial hole lined with polar residues
- proteins have to unfold to pass through
- FliD cap adds flagellin as it rotates
What is the order of flagella synthesis
MS/C ring Motor proteins P ring L ring Early hook Cap/ late Hook Hook filament junction
What is the subunit of flagella
Flagellin
