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PROSITE documentation PDOC00373 |
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 [1,2,3].
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 [4].
Some proteins known to contain LPxTG motif containing sorting signal are listed below:
The profile we developed covers the LPxTG motif, the hydrophobic stretch and the positively charged region.
Note:This profile replaces a pattern whose specificity was inadequate.
Last update:July 2018 / Profile revised.
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PROSITE method (with tools and information) covered by this documentation:
1 | Authors | Mazmanian S.K. Liu G. Ton-That H. Schneewind O. |
Title | Staphylococcus aureus sortase, an enzyme that anchors surface proteins to the cell wall. | |
Source | Science 285:760-763(1999). | |
PubMed ID | 10427003 |
2 | Authors | Ton-That H. Liu G. Mazmanian S.K. Faull K.F. Schneewind O. |
Source | Proc. Natl. Acad. Sci. U.S.A. 96:12424-12429(1999). |
3 | Authors | Perry A.M. Ton-That H. Mazmanian S.K. Schneewind O. |
Title | Anchoring of surface proteins to the cell wall of Staphylococcus aureus. III. Lipid II is an in vivo peptidoglycan substrate for sortase-catalyzed surface protein anchoring. | |
Source | J. Biol. Chem. 277:16241-16248(2002). | |
PubMed ID | 11856734 | |
DOI | 10.1074/jbc.M109194200 |
4 | Authors | Poulsen K. Reinholdt J. Jespersgaard C. Boye K. Brown T.A. Hauge M. Kilian M. |
Title | A comprehensive genetic study of streptococcal immunoglobulin A1 proteases: evidence for recombination within and between species. | |
Source | Infect. Immun. 66:181-190(1998). | |
PubMed ID | 9423856 |