Family G6
Summary for family G6
| Family type peptidase | G06.001 - Ras/Rap1-specific peptidase (Vibrio vulnificus), MEROPS Accession MER0441632 (peptidase unit: 3596-4089) |
| Content of family | Family G6 contains an endopeptidase that cleaves host proteins |
| History | Infection by the gram-negative bacterium Vibrio vulnificus can result in cellulitis and sepsis. The MARTX (multifunctional-autoprocessing repeats-in-toxin) cytotoxin of V. vulnificus is a large, mutidomain protein that processes itself. Self-processing is performed by a cysteine peptidase (#C80.001#). One of the released domains, known as RRSP (Ras/Rap1-specific endopeptidase), also functions as an endopeptidase, cleaving the switch I domain of host GTPases Ras and Rap1 (Biancucci et al., 2018). |
| Catalytic type | Glutamic |
| Active site | Active site residues have been identified by site-directed mutagenesis as Glu3900, His3902, Glu3930, and His4030 (Biancucci et al., 2018). No metal ions were found in the structure, and activity is unaffected by EDTA and1,10-phenanthroline (Biancucci et al., 2018). RRSP is therefore not a metallo-dependent enzyme, unlike the structurally related erythromycin esterase EreA. |
| Activities and specificities | Ras is cleaved in the switch I region by RRSP, but the N-terminal fragment remains attached to the complex (Antic et al., 2015). |
| Molecular structure | The tertiary structure of the RRSP domain has been solved and shows an alpha/beta fold simialr to enzymes from the EreA/ChaN-like superfamily, including the erythromycin esterases EreA and EreB and the peptidase Tiki (#G04.001#) (Biancucci et al., 2018). Families G4 and G6 are therefore included in the same clan. |
| Clan | GC |
|
Distribution of family
|
Bacteria |
details |
|
|
|
Archaea |
- |
|
|
|
Protozoa |
- |
|
|
|
Fungi |
- |
|
|
|
Plants |
- |
|
|
|
Animals |
- |
|
|
|
Viruses |
- |
|
