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peptidoglycan biosynthetic process

Definition

Target type: biologicalprocess

The chemical reactions and pathways resulting in the formation of peptidoglycans, any of a class of glycoconjugates found in bacterial cell walls. [http://www.dsmz.de/species/murein.htm, ISBN:0198506732]

Peptidoglycan biosynthesis is a complex process that involves the assembly of a unique polymer called peptidoglycan, which forms the rigid, protective layer surrounding the cell wall of bacteria. This process is essential for bacterial survival and is a major target for antibiotics.

The synthesis of peptidoglycan involves a series of steps, including:

**1. Synthesis of building blocks:**

* **N-acetylmuramic acid (NAM) and N-acetylglucosamine (NAG):** These sugars are the building blocks of peptidoglycan and are synthesized separately. NAM is formed by the addition of a lactyl group to NAG.
* **Peptides:** Short chains of amino acids are synthesized and attached to NAM. The specific sequence of amino acids varies depending on the bacterial species.

**2. Assembly of the peptidoglycan precursor:**

* NAM and NAG are linked together to form a disaccharide unit.
* The peptide chain attached to NAM is extended by the addition of more amino acids.
* This disaccharide-peptide unit is then attached to a carrier molecule called undecaprenyl phosphate (Und-P), forming a lipid-linked precursor.

**3. Translocation across the membrane:**

* The lipid-linked precursor is transported across the bacterial cell membrane by a flippase enzyme.

**4. Incorporation into the peptidoglycan layer:**

* The lipid-linked precursor is incorporated into the growing peptidoglycan chain by a transglycosylase enzyme, which links the disaccharide units together.
* A transpeptidase enzyme then forms cross-links between the peptide chains attached to different NAM units, strengthening the peptidoglycan structure.

**5. Recycling of Und-P:**

* The carrier molecule, Und-P, is recycled for use in subsequent rounds of peptidoglycan synthesis.

**Regulation of peptidoglycan biosynthesis:**

* The synthesis of peptidoglycan is tightly regulated by a variety of mechanisms, including feedback inhibition, allosteric regulation, and the activity of specific regulatory proteins.

**Antibiotic targets:**

* Many antibiotics target peptidoglycan biosynthesis. For example, penicillin and its derivatives block the activity of transpeptidases, inhibiting the formation of cross-links between peptide chains. Vancomycin inhibits the incorporation of peptidoglycan precursors into the growing peptidoglycan chain.

**Conclusion:**

Peptidoglycan biosynthesis is a vital process for bacterial survival. It involves the synthesis and assembly of a unique polymer that forms the rigid cell wall. This process is a major target for antibiotics, making it a crucial area of research in the fight against bacterial infections.'
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Proteins (9)

ProteinDefinitionTaxonomy
Undecaprenyl-diphosphataseAn undecaprenyl-diphosphatase that is encoded in the genome of Escherichia coli K-12. [PRO:DNx, UniProtKB:P60932]Escherichia coli K-12
Peptidoglycan D,D-transpeptidase MrdAA peptidoglycan D,D-transpeptidase MrdA that is encoded in the genome of Escherichia coli K-12. [PRO:DNx, UniProtKB:P0AD65]Escherichia coli K-12
Peptidoglycan D,D-transpeptidase MrdAA peptidoglycan D,D-transpeptidase MrdA that is encoded in the genome of Escherichia coli K-12. [PRO:DNx, UniProtKB:P0AD65]Escherichia coli K-12
UDP-N-acetylglucosamine 1-carboxyvinyltransferaseA UDP-N-acetylglucosamine 1-carboxyvinyltransferase that is encoded in the genome of Escherichia coli K-12. [PRO:DNx, UniProtKB:P0A749]Escherichia coli K-12
UDP-N-acetylglucosamine 1-carboxyvinyltransferaseA UDP-N-acetylglucosamine 1-carboxyvinyltransferase that is encoded in the genome of Escherichia coli K-12. [PRO:DNx, UniProtKB:P0A749]Escherichia coli K-12
Phospho-N-acetylmuramoyl-pentapeptide-transferaseA phospho-N-acetylmuramoyl-pentapeptide-transferase that is encoded in the genome of Escherichia coli K-12. [PRO:DNx, UniProtKB:P0A6W3]Escherichia coli K-12
Alanine racemase, biosyntheticAn alanine racemase, biosynthetic that is encoded in the genome of Escherichia coli K-12. [PRO:DNx, UniProtKB:P0A6B4]Escherichia coli K-12
UDP-N-acetylenolpyruvoylglucosamine reductaseA UDP-N-acetylenolpyruvoylglucosamine reductase that is encoded in the genome of Escherichia coli K-12. [PRO:DNx, UniProtKB:P08373]Escherichia coli K-12
UDP-N-acetylenolpyruvoylglucosamine reductaseA UDP-N-acetylenolpyruvoylglucosamine reductase that is encoded in the genome of Escherichia coli K-12. [PRO:DNx, UniProtKB:P08373]Escherichia coli K-12

Compounds (15)

CompoundDefinitionClassesRoles
alaninealanine : An alpha-amino acid that consists of propionic acid bearing an amino substituent at position 2.

Alanine: A non-essential amino acid that occurs in high levels in its free state in plasma. It is produced from pyruvate by transamination. It is involved in sugar and acid metabolism, increases IMMUNITY, and provides energy for muscle tissue, BRAIN, and the CENTRAL NERVOUS SYSTEM.
alanine;
alanine zwitterion;
L-alpha-amino acid;
proteinogenic amino acid;
pyruvate family amino acid
EC 4.3.1.15 (diaminopropionate ammonia-lyase) inhibitor;
fundamental metabolite
1,2-diphenyl-3,5-pyrazolidinedione1,2-diphenyl-3,5-pyrazolidinedione: structure given in first source
bromonitromethanebromonitromethane: structure in first source
alantolactonealantolactone : A sesquiterpene lactone that is 3a,5,6,7,8,8a,9,9a-octahydronaphtho[2,3-b]furan-2-one bearing two methyl substituents at positions 5 and 8a as well as a methylidene substituent at position 3.

alantolactone: allergenic sesquiterpene lactone; crystalline mixture of alantolactones from group of sesquiterpenes; structure
naphthofuran;
olefinic compound;
sesquiterpene lactone
antineoplastic agent;
apoptosis inducer;
plant metabolite
dehydrocostus lactonedehydrocostus lactone : An organic heterotricyclic compound and guaianolide sesquiterpene lactone that is acrylic acid which is substituted at position 2 by a 4-hydroxy-3,8-bis(methylene)decahydoazulen-5-yl group and in which the hydroxy group and the carboxy group have undergone formal condensation to afford the corresponding gamma-lactone.gamma-lactone;
guaiane sesquiterpenoid;
organic heterotricyclic compound;
sesquiterpene lactone
antimycobacterial drug;
antineoplastic agent;
apoptosis inducer;
cyclooxygenase 2 inhibitor;
metabolite;
trypanocidal drug
parthenolidegermacranolide
cynaropicrincynaropicrin: structure given in first source; RN given for ((3aR-(3aalpha,4alpha,6aalpha,8beta,9aalpha,9bbeta)))-isomersesquiterpene lactone
phenylalanine arginine beta-naphthylamidephenylalanine arginine beta-naphthylamide: a drug efflux pump inhibitor; structure in first sourcepeptide
fosfomycinfosfomycin : A phosphonic acid having an (R,S)-1,2-epoxypropyl group attached to phosphorus.

Fosfomycin: An antibiotic produced by Streptomyces fradiae.
epoxide;
phosphonic acids
antimicrobial agent;
EC 2.5.1.7 (UDP-N-acetylglucosamine 1-carboxyvinyltransferase) inhibitor
costunolidegermacranolide;
heterobicyclic compound
anthelminthic drug;
antiinfective agent;
antineoplastic agent;
antiparasitic agent;
antiviral drug;
metabolite
eupatoriopicrinegermacranolide
capuramycincapuramycin: from Streptomyces griseus 446-S3; structure given in first source
2-bromo-5-(2-bromo-2-nitrovinyl)furan2-bromo-5-(2-bromo-2-nitrovinyl)furan: structure in first source
baci-imhomodetic cyclic peptide;
polypeptide;
zwitterion
antibacterial agent;
antimicrobial agent
nxl 104avibactam sodium : An organic sodium salt that is the monosodium salt of avibactam. Used in combination with ceftazidime pentahydrate for the treatment of complicated urinary tract infections including pyelonephritis.organic sodium saltantibacterial drug;
antimicrobial agent;
EC 3.5.2.6 (beta-lactamase) inhibitor