Lecture 9

Question 1

What does ABC transport stand for?

Answer 1

ATP binding cassette

Question 2

ABC transport across what membrane?

Answer 2

the inner membrane

Question 3

What are the three proteins used in ABC transport system?

Answer 3

periplasmic binding protein, membrane spanning transporter, ATP hydrolyzing protein

Question 4

What does the periplasmic binding protein do in ABC transport?

Answer 4

binds a specific compound and carries it across the periplasm to the inner membrane.

Question 5

What does the membrane spanning transporter do?

Answer 5

contains a channel thru which the specific compound can move thru inner mem to cytoplasm

Question 6

What does ATP hydrolyzing protein do?

Answer 6

breaks down ATP to provide energy for compound to move thru the membrane spanning transporter

Question 7

What does hydrolyze mean?

Answer 7

adding h2o to break a bond

Question 8

what amino acid sequence does ATPase contain?

Answer 8

ATP binding cassette (ABC)

Question 9

a group of proteins that are structurally similar and are related on evolutionary basis

Answer 9

superfamily

Question 10

breaks down atp to allow pumping of antibiotics out of the cell

Answer 10

drug efflux system

Question 11

How is ATP broken down? (what kind of rxn) What does it break off?

Answer 11

hydrolytic rxn; water is used to break off a phosphate

Question 12

What kind of reaction is ATP hydrolysis?

Answer 12

exergonic rxn

Question 13

heme transport is found in what organism?

Answer 13

Plesiomonas shigelloides

Question 14

what is a cytochrome?

Answer 14

heme containing protein

Question 15

Where is heme found in humans and animals?

Answer 15

hemoglobin and myoglobin and cytochromes

Question 16

cytochromes are also involved in what?

Answer 16

metabolism

Question 17

iron w an organic shell (organic iron)

Answer 17

heme iron

Question 18

elemental iron (inorganic)

Answer 18

Fe

Question 19

What two transports are used in the heme transport system?

Answer 19

TonB dependent transport and ABC transport

Question 20

Is P. shigelloides gram pos or neg? what kind of pathogen is it?

Answer 20

negative; intestinal

Question 21

What does P. shigelloides cause?

Answer 21

cholera-like disease: excessive watery diarrhea
or dysentery-like disease w diarrhea w mucus, blood, and cramping

Question 22

TonB dependent transport is across what membrane?

Answer 22

outer

Question 23

ABC transport is across what membrane?

Answer 23

inner

Question 24

What is TonB powered by?

Answer 24

proton motive force

Question 25

In ABC transport what is HugB? (1st protein carries it to #2)

Answer 25

periplasmic heme binding protein

Question 26

In ABC transport, what is Hug C (protein #2 in the inner mem)

Answer 26

membrane spanning transporter

Question 27

in ABC transport, what is Hug D? (last enzyme)

Answer 27

ATP hydrolyzing enzyme

Question 28

In the heme transport system, what is Hug A? (very 1st step on the outer mem)

Answer 28

heme receptor; binds and transports it into the cell

Question 29

HugA is a polymer of _______________ and hugA is a polymer of nucleotides

Answer 29

amino acids

Question 30

What other compounds are transported like heme? (using TonB and ABC transport)

Answer 30

vitamin B12 and iron siderophore complexes

Question 31

what are siderophores? What do they allow the bacteria to do?

Answer 31

organic molecules that bacteria make and secrete that have a high affinity for iron. Allow bac to acquire iron from the environment.

Question 32

What siderophore is produced by E. coli?

Answer 32

Enterobactin

Question 33

The double bonds/ OHs in the siderophore allow the molecule to become __________, unlike those in a ____________which do not do this.

Answer 33

ionic; sugar

Question 34

What does becoming ionic allow the enterobactin to do?

Answer 34

form ionic bonds w ferric iron (Fe3+), giving enterobactin its high affinity for iron.

Question 35

When does E. coli release a siderophore?

Answer 35

when it is iron-stressed