Self Inhibition Prevention

Question 1

Self Inhibition prevention

Answer 1

Bacteria can produce cytotoxins, they must prevent these from harming themselves

Question 2

Mechanisms to avoid self inhibition

Answer 2

Self-resistance genes, efflux systems, compartmentalization and pathway regulation.

Question 3

Actinorhodin (ACT)

Answer 3

Polyketide, pH-dependent antibiotic with potent antibacterial properties.

Question 4

Bacteria that produces actinorhodin

Answer 4

Streptomyces coelicolour, act gene cluster.

Question 5

pH dependent antibiotic

Answer 5

Antimicrobial activity varies with pH, affecting effectiveness in different bodies and sites.

Question 6

Enzyme responsible for ACT.

Answer 6

ACT synthase, by using succession condensation reactions.

Question 7

Regulator genes of ACT

Answer 7

bldA and afsR, depending on the growth phase.

Question 8

act pathway regulators.

Answer 8

ActII-ORF4, which binds to promoters of ACT biosynthesis in certain conditions.

Question 9

S. coelicoloer self-resistance with effluxation.

Answer 9

The actA gene encodes an efflux transporter (extremely specific), that rids a cell of ACT.

Question 10

Other self-resistance with modification enzymes

Answer 10

Enzymes are produced in defense to SMs, which deactivate (detoxify) SMs, such as macrolide.

Question 11

Conditions where S. coelicolour produces ACT.

Answer 11

Alkaline conditions, aas well as certain intermediate molecular signaling, caused by SM stress from other SMs.