Chapter 5.3 MreB and Cell Morphology

Question 1

What kind of cell cytoskeleton do prokaryotes contain?

Answer 1

Their cytoskeleton is dynamic and multifaceted

Question 2

What is the major shape-determining factor in prokaryotes?

Answer 2

MreB

• is a protein found in bacteria that has been identified as a homologue (homologue means that its a structure that exists in other organisms in a different form) of actin, as indicated by similarities in tertiary structure and conservation of active site peptide sequence.

Question 3

MreB forms what structure, and what is found in?

Answer 3

Forms simple cytoskeleton in Bacteria and probably Archaea

Forms spiral-shaped bands around the inside of the cell, underneath the cytoplasmic membrane

Not found in coccus-shaped bacteria

REVIEW:

Shapes of bacteria cells:
Coccus(Spherical Shaped)
Bacillus (Rod Shaped)
Spirillum (Spiral Shaped)

Question 4

MreB also synthesizes new ___________ and other cell wall components to specific locations along the cylinder of a rod-shaped (Bacillus) cell during growth.

Answer 4

Peptidoglycan

Question 5

What is the shape-determining protein produced by vibro-shaped (Comma Shaped) cells of Caulobacter crescentus

Answer 5

Crescentin

Question 6

Crescentin protein organizes into _______ ~10nm wide that localize on the concave face of the cell

Answer 6

filaments

Question 7

Most archael genomes contain _________ and _________-like proteins; thus, cell morphology is similar to that seen in what?

Answer 7

FtsZ and MreB

Bacteria