Family C82
Summary for family C82
| Family type peptidase | C82.001 - L,D-transpeptidase (Enterococcus-type) (Enterococcus faecium), MEROPS Accession MER0076166 (peptidase unit: 217-466) |
| Content of family | Family C82 contains enzymes that hydrolase (and transfer) bacterial cell wall peptides. |
| History |
Identifier created: MEROPS 7.9 (17 September 2007)
During the final stages of cell-wall synthesis in bacteria, D,D-transpeptidases catalyse the cross-linking of peptide chains from adjacent glycan strands of nascent peptidoglycan. The D,D-transpeptidases are inhibited by antibiotics like penicillin and ampicillin. An ampicillin-resistant mutant of Enterococcus faecium was found to express a beta-lactam-insensitive LD-transpeptidase, termed Ldt(fm) (Mainardi et al., 2000). Homologous enzymes occur widely in bacteria, and some of them can act as peptide hydrolases as well as transpeptidases. |
| Catalytic type | Cysteine |
| Active site | Active site residues His421 and Cys442 (see the Alignment) were identified crystallographically by Biarrotte-Sorin et al. (2006). |
| Activities and specificities | The L,D-transpeptidase of Enterococcus faecalis (known as Ldt(fs)) was shown to hydrolyse the L-Lys(3)-D-Ala(4) bonds of bacterial cell wall components, including the tetrapeptide and pentapeptide stems; the protein also showed cell-wall cross-linking activity (Magnet et al., 2007). |
| Molecular structure | The structure of a fragment of the L,D-transpeptidase of Enterococcus faecium was determined by Biarrotte-Sorin et al. (2006). The active site residues were seen to occur in the so-called ErfK/YbiS/YhnG domain, as they do in the Escherichia coli protein ykuD and the sortases (family C60). As a result, family C82 is placed in clan CL. |
| Clan | CL |
| Basis of clan assignment | Active site residues for members of this family and family C60 occur in the same order in the sequence: H, C. |
|
Distribution of family
|
Bacteria |
details |
|
|
|
Archaea |
- |
|
|
|
Protozoa |
- |
|
|
|
Fungi |
- |
|
|
|
Plants |
details |
|
|
|
Animals |
details |
|
|
|
Viruses |
- |
|
| Peptidases and Homologues |
MEROPS ID |
Structure |
| L,D-transpeptidase (Enterococcus-type) | C82.001 | Yes |
| Ldt(fs) transpeptidase | C82.002 | - |
| LdtF protein (Escherichia coli) | C82.A01 | - |
| ECBD_1659 protein (Escherichia coli) | C82.A02 | - |
| YnhG protein (Escherichia coli) | C82.A03 | - |
| YbiS protein (Escherichia coli) | C82.A04 | - |
| YcfS protein (Escherichia coli) | C82.A05 | - |
| Subfamily C82A non-peptidase homologues | non-peptidase homologue | - |
| Subfamily C82A unassigned peptidases | unassigned | Yes |
|
Peptidases not assigned to subfamily
|
