Domain

Gram-positive LPXTG cell wall anchor (IPR019948)

Short name: Gram-positive_anchor

Domain relationships

Description

Surface proteins from Gram-positive cocci are covalently linked to the bacterial cell wall by sortase, a membrane-anchored transpeptidase that cleaves proteins between the threonine and the glycine of a conserved LPxTG motif, with the formation of a thioester between the conserved cysteine of sortase and the threonine carboxyl group. The newly liberated C terminus of the threonine is transferred via an amide bond exchange to the amino group of the pentaglycine wall crossbridge, thereby tethering the C terminus end of the surface protein to the bacterial peptidoglycan [PMID: 10427003, PMID: 11856734].

Surface proteins from Gram-positive cocci contain an N-terminal signal peptide and a C-terminal sorting signal. The 35-residue sorting signal is composed of a conserved LPxTG motif, a hydrophobic domain, and a tail of positively charged residues. This structure is represented in the following schematic representation:


                                           +-- sorting signal ---+
                                           |                     |
  +------+---------------------------------+-----+-------------+-+
  |Signal|                                 |LPxTG| Hydrophobic |+|
  +------+---------------------------------+-----+-------------+-+

  'Signal': signal peptide;
  'Hydrophobic': hydrophobic domain;
  '+': positive charged tail.

In the case of immunoglobulin A1 proteases, the typical Gram-positive cell wall anchor motif LPxTG is located in their N-terminal regions, in contrast with other known streptococcal and staphylococcal proteins [PMID: 9423856].

This domain covers the LPxTG motif, the hydrophobic stretch and the positively charged region.

Contributing signatures

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