Endolysin
Encyclopedia
Endolysin is a generic term describing an enzyme that degrades the bacterial peptidoglycan
cell wall, resulting in lysis of the bacterial cell.
At the end of the bacteriophage
replication cycle, bacteriophages have to release their newly formed progeny. The major barrier to overcome is the peptidoglycan
. To degrade this layer, bacteriophages contain endolysins.
Depending on the bond these enzymes cleave, we can distinguish muramidases (lysozyme
), transglycosylases, amidase
s or endopeptidase
s.
Peptidoglycan
Peptidoglycan, also known as murein, is a polymer consisting of sugars and amino acids that forms a mesh-like layer outside the plasma membrane of bacteria , forming the cell wall. The sugar component consists of alternating residues of β- linked N-acetylglucosamine and N-acetylmuramic acid...
cell wall, resulting in lysis of the bacterial cell.
At the end of the bacteriophage
Bacteriophage
A bacteriophage is any one of a number of viruses that infect bacteria. They do this by injecting genetic material, which they carry enclosed in an outer protein capsid...
replication cycle, bacteriophages have to release their newly formed progeny. The major barrier to overcome is the peptidoglycan
Peptidoglycan
Peptidoglycan, also known as murein, is a polymer consisting of sugars and amino acids that forms a mesh-like layer outside the plasma membrane of bacteria , forming the cell wall. The sugar component consists of alternating residues of β- linked N-acetylglucosamine and N-acetylmuramic acid...
. To degrade this layer, bacteriophages contain endolysins.
Depending on the bond these enzymes cleave, we can distinguish muramidases (lysozyme
Lysozyme
Lysozyme, also known as muramidase or N-acetylmuramide glycanhydrolase, are glycoside hydrolases, enzymes that damage bacterial cell walls by catalyzing hydrolysis of 1,4-beta-linkages between N-acetylmuramic acid and N-acetyl-D-glucosamine residues in a peptidoglycan and between...
), transglycosylases, amidase
Amidase
In enzymology, an amidase is an enzyme that catalyzes the hydrolysis of an amide:Thus, the two substrates of this enzyme are monocarboxylic acid amide and H2O, whereas its two products are monocarboxylate and NH3....
s or endopeptidase
Endopeptidase
Endopeptidase or endoproteinase are proteolytic peptidases that break peptide bonds of nonterminal amino acids , in contrast to exopeptidases, which break peptide bonds from their end-pieces. For this reason, endopeptidases cannot break down peptides into monomers, while exopeptidases can break...
s.