Domain

Retropepsin Saci-like domain (IPR034132)

Short name: RP_Saci-like

Overlapping homologous superfamilies

Domain relationships

None.

Description

This entry includes the peptidase domains of retropepsin-like aspartic endopeptidases from retrotransposons with long terminal repeats (LTR) including Saci-1, -2 and -3 of Schistosoma mansoni [PMID: 14990715]. Retropepsins are related to fungal and mammalian pepsins. While fungal and mammalian pepsins are bilobal proteins with structurally related N- and C-termini, retropepsins are half as long as their fungal and mammalian counterparts. The monomers are structurally related to one lobe of the pepsin molecule and retropepsins function as homodimers. The active site aspartate occurs within a motif (Asp-Thr/Ser-Gly), as it does in pepsin. Asp residues are ligands of an activated water molecule in all examples where catalytic residues have been identified. Retrotransposon aspartic endopeptidase is synthesized as part of a polyprotein that also contains a reverse transcriptase and an integrase. The polyprotein is presumed to undergo specific enzymatic cleavage to yield the mature proteins. This group of aspartic endopeptidases is classified by MEROPS as the peptidase family A28, subfamily A28B [PMID: 16098038].

Contributing signatures

Signatures from InterPro member databases are used to construct an entry.
CDD