View the latest EBI news stories and important announcements...

Search The CSA
EC Number

Catalytic Site Atlas

CSA LITERATURE entry for 1fy2

E.C. namedipeptidase E
SpeciesSalmonella typhimurium (Bacteria)
E.C. Number (IntEnz)
CSA Homologues of 1fy21fye,3en0,
CSA Entries With UniProtID P36936
CSA Entries With EC Number
PDBe Entry 1fy2
PDBSum Entry 1fy2
MACiE Entry 1fy2

Literature Report

IntroductionAspartyl peptidase has unique substrate specificity for Asp-X dipeptides and asp-gly-gly tripeptide. Not classified in any known peptidase family. Convergent evolution accounts for catalytic triad His 157 Ser 120 Glu 192. Found in bacteria and recently found to be present in isolated eukaryotes.
MechansimNucleophilic attack by activated ser120 on peptide bond. Protonation of leaving group by His 157. Transition state stabilisation by oxyanion hole (ala 121 and gly 88); hydrolysis of acyl enzyme intermediate by His 157 activated water molecule.

Catalytic Sites for 1fy2

Annotated By Reference To The Literature - Site 1 (Perform Site Search)
ResidueChainNumberUniProtKB NumberFunctional PartFunctionTargetDescription
GluA192192macie:sideChainPositions His 157 correctly for acid-base catalysis.
AlaA121121macie:mainChainAmideStabilise the transition state via oxyanion hole
SerA120120macie:sideChainNucleophilic attack upon peptide bond forms covalent intermediate. This intermediate is broken up by a nucleophilic attack from water.
GlyA8888macie:mainChainAmideStabilise the transition state via oxyanion hole
HisA157157macie:sideChainDeprotonates Ser 120 to allow the nucleophilic attack. Protonates the leaving group. Activates water for nucleophilic attack.

Literature References

Lassy RA
Peptidase E, a peptidase specific for N-terminal aspartic dipeptides, is a serine hydrolase.
J Bacteriol 2000 182 2536-2543
PubMed: 10762256
HÃ¥kansson K
The structure of aspartyl dipeptidase reveals a unique fold with a Ser-His-Glu catalytic triad.
Proc Natl Acad Sci U S A 2000 97 14097-14102
PubMed: 11106384