Protein Family Models

This entry represents the autochaperone domain of type 1 (AC-1) in the Type Va Secretion System (T5aSS). Autotransporters (ATs) belong to a family of modular proteins secreted by the Type V, subtype a, secretion system (T5aSS) and considered as an important source of virulence factors in lipopolysaccharidic diderm bacteria (archetypical Gram-negative bacteria). The AC of type 1 with beta-fold appears as a prevalent and conserved structural element exclusively associated to beta-helical AT passenger [1]. [1]. 29375499. Identification of the Autochaperone Domain in the Type Va Secretion System (T5aSS): Prevalent Feature of Autotransporters with a beta-Helical Passenger. Rojas-Lopez M, Zorgani MA, Kelley LA, Bailly X, Kajava AV, Henderson IR, Polticelli F, Pizza M, Rosini R, Desvaux M;. Front Microbiol. 2018;8:2607. (from Pfam)

Date:

2024-10-16

Secretion of protein products occurs by a number of different pathways in bacteria. One of these pathways known as the type V pathway was first described for the IgA1 protease [2]. The protein component that mediates secretion through the outer membrane is contained within the secreted protein itself, hence the proteins secreted in this way are called autotransporters. This family corresponds to the presumed integral membrane beta-barrel domain that transports the protein. This domain is found at the C terminus of the proteins it occurs in. The N terminus contains the variable passenger domain that is translocated across the membrane. Once the passenger domain is exported it is cleaved auto-catalytically in some proteins, in others a different protease is used and in some cases no cleavage occurs [1]. [1]. 9778731. The great escape: structure and function of the autotransporter proteins. Henderson IR, Navarro-Garcia F, Nataro JP;. Trends Microbiol 1998;6:370-378. [2]. 3027577. Gene structure and extracellular secretion of Neisseria gonorrhoeae IgA protease. Pohlner J, Halter R, Beyreuther K, Meyer TF;. Nature 1987;325:458-462. [3]. 11980709. Export of autotransported proteins proceeds through an oligomeric ring shaped by C-terminal domains. Veiga E, Sugawara E, Nikaido H, de Lorenzo V, Fernandez LA;. EMBO J 2002;21:2122-2131. [4]. 15014442. Structure of the translocator domain of a bacterial autotransporter. Oomen CJ, Van Ulsen P, Van Gelder P, Feijen M, Tommassen J, Gros P;. EMBO J 2004;23:1257-1266. (from Pfam)

Date:

2024-10-16

Date:

2024-08-14

Date:

2022-06-07

A number of Gram-negative bacterial proteins, mostly found in pathogens and associated with virulence, contain a conserved C-terminal domain that integrates into the outer membrane and enables the N-terminal region to be delivered across the membrane. This C-terminal autotransporter domain is about 400 amino acids in length and includes the aromatic amino acid-rich OMP signal, typically ending with a Phe or Trp residue, at the extreme C-terminus.

Date:

2024-06-21