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Catalytic Site Atlas

CSA LITERATURE entry for 1p4n

E.C. nameUDP-N-acetylmuramoylpentapeptide-lysine N6-alanyltransferase
SpeciesWeissella viridescens ()
E.C. Number (IntEnz)
CSA Homologues of 1p4n1ne9,1xe4,1xf8,1xix,
CSA Entries With UniProtID
CSA Entries With EC Number
PDBe Entry 1p4n
PDBSum Entry 1p4n
MACiE Entry 1p4n

Literature Report

IntroductionFemX uses aminoacyl-tRNA as an amino acid donor to synthesise the peptide cross-bridge in peptidoglycan of gram-positive bacteria.
FemX belongs to the Fem family of nonribosomal peptidyl transferases. They are targets of beta-lactam antibiotics.
MechansimFemX catalyses the transfer of L-Ala onto the cytoplasmic precursor UDP-N-acetyl-muramyl-pentapeptide. Lys 36 and Arg 211 activate the substrate by maintaining it in a bent conformation. UDP-N-acetyl-muramyl-pentapeptide (UDP-MPP) is bound, followed by Ala-tRNA. Nucleophilic attack occurs via activation by Asp 108 acting as a general base to abstract a proton from the amino group of the lysine residue of UDP-MPP, and attack occurs on the carbonyl of the aminoacylated-tRNA to generate a tetrahedral intermediate. Collapse of the tetrahedral intermediate is assisted by the action of Glu 319 as a general acid to protonate the 3'-OH of the tRNA ribose moiety.

Catalytic Sites for 1p4n

Annotated By Reference To The Literature - Site 1 (Perform Site Search)
ResidueChainNumberUniProtKB NumberFunctional PartFunctionTargetDescription
ArgA211212macie:sideChainActivates the substrate sterically.
GluA319320macie:sideChainActs as the general acid catalyst in protonation of the leaving group to failitate cleavage.
LysA3637macie:sideChainActivates the substrate sterically.
AspA108109macie:sideChainActs as a general base catalyst in activating the substrate for nucleophilic attack.

Literature References

Hegde SS
Kinetic and mechanistic characterization of recombinant Lactobacillus viridescens FemX (UDP-N-acetylmuramoyl pentapeptide-lysine N6-alanyltransferase).
J Biol Chem 2003 278 22861-22867
PubMed: 12679335
Maillard AP
Structure-based site-directed mutagenesis of the UDP-MurNAc-pentapeptide-binding cavity of the FemX alanyl transferase from Weissella viridescens.
J Bacteriol 2005 187 3833-3838
PubMed: 15901708