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The V. fischeri Autoinducer
N-(b-ketocaproyl)-L-homoserine lactone
Quorum Sensing
LuxI
LuxR
LuxR
target gene
Acyl-Homoserine Lactone Autoinducers
LuxI-LuxR Quorum Sensing Systems
V. fischeri
Density dependent luminescence
P.aeruginosa
Virulence factors
A. tumefaciens
Conjugal transfer of Ti plasmid
E. carotovora
Antibiotic synthesis
Quorum Sensing in V. harveyi
AI-2
LuxQ
LuxP
H
D
H
LuxU
H
AI-1
D
HTH
LuxO
D
LuxN
LuxR
LuxCDABE
Quorum Sensing in E. coli and Salmonella
Bacteria That Contain luxS
Bacillus anthracis
Klebsiella pneumoniae
Shewanella putrefaciens
Bacillus halodurans
Lactococcus lactis
Staphylococcus aureus
Bacillus subtilis
Leuconostoc oenos
Staphylococcus epidermidis
Borrelia burgdorferi
Listeria monocytogenes
Streptococcus gordonii
Campylobacter jejuni
Neisseria gonorrhoeae
Streptococcus mutans
Clostridium acetobolyticum
Neisseria meningitidis
Streptococcus pneumoniae
Clostridium difficile
Pasteurella multocida
Streptococcus pyogenes
Clostridium perfringens
Porphyromonas gingivalis
Vibrio anguillarum
Deinococcus radiodurans
Proteus mirabilis
Vibrio cholerae
Escherichia coli
Salmonella paratyphi
Vibrio harveyi
Enterococcus faecalis
Salmonella typhi
Vibrio vulnificus
Haemophilus influenzae
Salmonella typhimurium
Yersinia pestis
Helicobacter pylori
luxS
metK
pfs
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MetK
Pfs
Pfs
SAM Utilization
Met
MetK
SAM
SAH
MTA
Pfs
SRH
4,5-Dihydroxy2,3-pentanedione
+ HC
Pfs
MTR
?
SAM Utilization
Met
MetK
SAM
SAH
MTA
Pfs
SRH
Pfs
MTR
LuxS?
4,5-Dihydroxy2,3-pentanedione
+ HC
?
SAM Utilization
Met
MetK
SAM
SAH
MTA
Pfs
SRH
Pfs
MTR
LuxS
AI-2 + HC
?
The LuxS Reaction
SRH
4,5-Dihydroxy+
2,3-pentanedione
Homocysteine
AI-2 Could be a Furanone
MHF
DMHF
HF
DHCP
Quorum Sensing in V. harveyi
AI-2
LuxQ
LuxP
H
D
H
LuxU
H
AI-1
D
HTH
LuxO
D
LuxN
LuxR
LuxCDABE
Holo-LuxP
Boron is ubiquitous in the biosphere
Sea water
L.A. tap water
Soils
Marine plants
Land plants
Marine animals
Land animals
0.4 mM (primarily boric acid)
40 μM
2-100 ppm
120 ppm
50 ppm
20-50 ppm
0.5 ppm
Boron is required by a number of organisms,
but for poorly characterized reasons
Vascular plants
Diatoms
Cyanobacteria
Zebrafish
cell wall? pollination?
heterocyst formation
embryogenesis
11B
holo-LuxP
filtered
apo-LuxP
NMR
Synthesis of AI-2
Boric Acid Induces Lux in V. harveyi
Synthesis of AI-2
Targets of AI-2
Vibrio harveyi
Bioluminescence, Biofilms
Vibrio cholerae
Virulence, Biofilms
Salmonella typhimurium
ABC transporter
Salmonella typhi
Biofilms
Escherichia coli O157:H7
Type III Secretion (virulence)
Porphyromonas gingivalis
Hemin acquisition genes, virulence factors
Shigella flexneri
VirB (virulence factor)
Streptococcus pyogenes
Secreted protease
Actinobacillus actinomycetemcomitans
Periodontal virulence, Mixed-species biofilms
Photorhabdus luminescens
Antibiotic production
Neisseria meningitidis
Virulence/bacteremia
Borrelia burgdorferi
Virulence
Clostridium perfringens
Virulence
Campylobacter jejuni
Motility
Microarrays
Escherichia coli K12
Escherichia coli O157:H7
Vibrio cholerae El Tor
~300 genes
~400 genes
~70 genes (virulence regulon)
Biosynthesis of AI-1 and AI-2
Met
MetK
SAM
SAH
LuxI
LuxLM
MTA
Pfs
SRH
Pfs
MTR
LuxS
AI-2 + HC
?
AI-1
Quorum Sensing in V. harveyi
AI-2
LuxQ
LuxP
H
D
H
LuxU
H
AI-1
D
HTH
LuxO
D
LuxN
LuxR
LuxCDABE