Lecture 38: Two-component Signaling and Strep Mutans

Strep mutans

this is the principal bacterial pathogen in dental caries, sticks to your teeth and survives in mouth

glycolysis

Strep mutans uses ____ exclusively for energy

H2O2

At neutral pH, secretion of _____ by competitors limits the growth of S. mutans

acidogenic and aciduric

S. mutans is highly _____ and _____

antimicrobial peptides

these are 10-50 amino acids, have positive charge, and can insert into or pass through the bacterial membrane to stop bacteria

electrostatic interaction between the negatively charged membrane and the positively charged antimicrobial peptide creates a pore

peptide goes into bacterial cell and inhibits intracellular function

what are the 2 ways that antimicrobial peptides work to cause bacterial lysis

pores

many antimicrobial peptides make _____ causing them to leak and ultimately killing the cell

host or microorganisms

antimicrobial peptides can be release by the _____ or ________

positive

antimicrobial peptides have a ____ charge

2 component signaling

this is found in prokaryotes only, has a singal bind to something, autophosphrylation happens, and a transcription factor is released, allows them to be protected against antimicrobial peptides

histidine kinase

In 2 component signaling the sensor is usually a _____ _____

NO

is 2 component signaling found in animals?

Extracellular ligand binding domain, intracellular catalytic domain

these are the two parts to an enzyme linked membrane membrane receptor

tyrosine kinase

most common catalytic domains have ____ ___activity

negative, worse, protect

positively charged peptide no longer attracted to the negatively charged membrane

the way that 2 component signlaing worksin S. mutans is via CiaH (receptor), which makes the charge of the membrane less ________________, which allows the positively charged peptides to bind __________(better/worse), which helps __________(protect/kill) the bacteria

pumped out

pumped out

A way that ABC works in S mutans is taht it has antimicrobial peptides to be pumped in the cell, but then immediately __________ ____

dont

If the peptides win, you ______(do/don't) have caries

do

If S mutans wins, you ______(do/don't) have caries

for bacteria like S. mutans to evade the effects of antimicrobial peptides

why is two component signaling used