| Primary Identifier | IPR032074 | Type | Domain |
| Short Name | ACD_dom |
| description | Actin cross-linking domains (ACDs) are distinct domains found in several bacterial toxins, including the Vibrio cholerae MARTX toxin. ACDs are enzyme ligases that catalyse the formation of an irreversible iso-peptide bond on two actin molecules in an ATP- and Mg/Mn(2+)-dependent manner. Cross-linking depletes the cellular pool of G-actin leading to actin cytoskeleton depolymerisation [, ].The ACD has an overall V-shape. with the active site composed of five residues in a cleft located within the two arms of the V. The first subdomain, forming the left arm of the V, is mainly composed of β-strands, while the second subdomain, forming the right arm of the V, is helical. The first subdomain is composed of a central anti-parallel β-sheet of 8 β-strands, decorated by two adjacent small β-sheets, one above the centralβ-sheet and the second below. A long helix (α1) packs against strands β7-β4-βa5 from the central β-sheet, and strand β8 from the upper β-sheet. Finally, the terminal helix α9 packs against strands β2 and β9. The second subdomain is composed of 7 α-helices (α2-α8) and does not contain any β-strands []. |
