F
IPR005762

UDP-N-acetylmuramoylalanine-D-glutamate ligase MurD

InterPro entry
Short nameMurD
family relationships

Description

The bacterial cell wall provides strength and rigidity to counteract internal osmotic pressure, and protection against the environment. The peptidoglycan layer gives the cell wall its strength, and helps maintain the overall shape of the cell. The basic peptidoglycan structure of both Gram-positive and Gram-negative bacteria is comprised of a sheet of glycan chains connected by short cross-linking polypeptides. Biosynthesis of peptidoglycan is a multi-step (11-12 steps) process comprising three main stages:


 * (1) formation of UDP-N-acetylmuramic acid (UDPMurNAc) from N-acetylglucosamine (GlcNAc).
 * (2) addition of a short polypeptide chain to the UDPMurNAc.
 * (3) addition of a second GlcNAc to the disaccharide-pentapeptide building block and transport of this unit through the cytoplasmic membrane and incorporation into the growing peptidoglycan layer.


Stage two involves four key Mur ligase enzymes: MurC (
6.3.2.8
)
[1]
, MurD (
6.3.2.9
)
[2]
, MurE (
6.3.2.13
)
[3]
and MurF (
6.3.2.10
)
[4]
. These four Mur ligases are responsible for the successive additions of L-alanine, D-glutamate, meso-diaminopimelate or L-lysine, and D-alanyl-D-alanine to UDP-N-acetylmuramic acid
[6]
. All four Mur ligases are topologically similar to one another, even though they display low sequence identity. They are each composed of three domains: an N-terminal Rossmann-fold domain responsible for binding the UDPMurNAc substrate; a central domain (similar to ATP-binding domains of several ATPases and GTPases); and a C-terminal domain (similar to dihydrofolate reductase fold) that binds the incoming amino acid
[6]
. Residues found in the three domains (the Asp50, Lys130 (GKT motif), and Glu174 residues, MurC numbering) are involved in the catalytic process
[6]
. The conserved sequence motifs found in the four Mur enzymes also map to other members of the Mur ligase family, including folylpolyglutamate synthetase, cyanophycin synthetase and the capB enzyme from Bacillales
[5]
.

This entry represents UDP-N-acetylmuramoylalanine-D-glutamate ligase (MurD). MurD catalyses the addition of d-glutamate to the nucleotide precursor UDP-N-acetylmuramoyl-l-alanine.

References

1.Structure of Escherichia coli UDP-N-acetylmuramoyl:L-alanine ligase (MurC). Deva T, Baker EN, Squire CJ, Smith CA. Acta Crystallogr. D Biol. Crystallogr. 62, 1466-74, (2006). View articlePMID: 17139082

2.Targeted molecular dynamics simulation studies of binding and conformational changes in E. coli MurD. Perdih A, Kotnik M, Hodoscek M, Solmajer T. Proteins 68, 243-54, (2007). View articlePMID: 17427948

3.The MurE synthetase from Thermotoga maritima is endowed with an unusual D-lysine adding activity. Boniface A, Bouhss A, Mengin-Lecreulx D, Blanot D. J. Biol. Chem. 281, 15680-6, (2006). View articlePMID: 16595662

4.Structure of MurF from Streptococcus pneumoniae co-crystallized with a small molecule inhibitor exhibits interdomain closure. Longenecker KL, Stamper GF, Hajduk PJ, Fry EH, Jakob CG, Harlan JE, Edalji R, Bartley DM, Walter KA, Solomon LR, Holzman TF, Gu YG, Lerner CG, Beutel BA, Stoll VS. Protein Sci. 14, 3039-47, (2005). View articlePMID: 16322581

5.Structure, function and dynamics in the mur family of bacterial cell wall ligases. Smith CA. J. Mol. Biol. 362, 640-55, (2006). View articlePMID: 16934839

6.The MurC ligase essential for peptidoglycan biosynthesis is regulated by the serine/threonine protein kinase PknA in Corynebacterium glutamicum. Fiuza M, Canova MJ, Patin D, Letek M, Zanella-Cleon I, Becchi M, Mateos LM, Mengin-Lecreulx D, Molle V, Gil JA. J Biol Chem 283, 36553-63, (2008). PMID: 18974047

GO terms

Cross References

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