Sortase

Sortase refers to a group of <a href="/facts/Prokaryote/oYyvaDDH">prokaryotic</a> <a href="/facts/Enzyme/DSI1Fh7y">enzymes</a> that modify surface proteins by recognizing and cleaving a carboxyl-terminal <a href="/facts/Protein_targeting/R3B37xMM">sorting signal</a>. For most substrates of sortase enzymes, the recognition signal consists of the motif LPXTG (Leu-Pro-any-Thr-Gly), then a highly hydrophobic <a href="/facts/Transmembrane_domain/D1j0PwSR">transmembrane sequence</a>, followed by a cluster of basic residues such as <a href="/facts/Arginine/y49Hdf1e">arginine</a>. Cleavage occurs between the Thr and Gly, with transient attachment through the Thr residue to the active site Cys residue, followed by transpeptidation that attaches the protein covalently to cell wall components. Sortases occur in almost all <a href="/facts/Gram-positive_bacteria/H6WYQ17e">Gram-positive bacteria</a> and the occasional <a href="/facts/Gram-negative/S1PbVtp4">Gram-negative</a> bacterium (e.g. <a href="/facts/Shewanella_putrefaciens/HqpADgcK">Shewanella putrefaciens</a>) or <a href="/facts/Archaea/Adxh0aHw">Archaea</a> (e.g. <a href="/facts/Methanobacterium/WXCC0nSk">Methanobacterium thermoautotrophicum</a>), where cell wall LPXTG-mediated decoration has not been reported. Although sortase A, the "housekeeping" sortase, typically acts on many protein targets, other forms of sortase recognize variant forms of the cleavage motif, or catalyze the assembly of <a href="/facts/Pilin/Ir8uVq3K">pilins</a> into <a href="/facts/Pilus/xCNEXUdy">pili</a>.

Sortase open-in-new

Sortase