Peptidoglycan and Bacterial Cell Division

peptidoglycan

cell wall that surrounds bacteria that gives shape and protects against lysis

useful for identifying with gram stain

peptidoglycan hydrolase

these are important for growth and cell division

cleave PG crosslinks to make space for new PG strand insertions

pentapeptide

chain of 5 amino acids extending from NAM of peptidoglycan

disaccharide

NAG and NAM of peptidoglycan

gram positive

bacteria with a thick PG wall (20 layers)

gram negative

bacteria with only 1 layer of PG, have outer membrane as well

tracheal cytotoxin

disaccharide tetrapeptide with modified NAM residue that itself damages ciliated cells to cause whooping cough

PG hydrolases

these are needed for phage and predator lysins, cell separation, cell growth, and to make holes for flagella and pili

Many different types of these because many different bonds need to be cut

temperature sensitive mutants

These types of mutants affect folding by introducing a single aa substitution to make unfolded protein

null mutant

This mutation would knock out the gene and if the gene was essential like in division then it would be lethal

FtsZ

protein that is a tubulin homolog that creates mid-cell ring in first event of division

recruits other proteins and moves by treadmilling to guide PG synthesis enzymes around septum

FtsZ:GTP

this monomer binds to lead

FtsZ:GDP

this monomer dissociates at back

ftsW

PG transglycosylase

makes glycan chain

ftsI

PG transpeptidase

catalyze peptide bond crosslinks between two adjacent glycan chains

AmiA and EnvC

these two proteins work together to carefully digest septal PG