Protein Family Models

The Type II secretion system, also called Secretion-dependent pathway (SDP), is responsible for the transport of proteins across the outer membrane first exported to the periplasm by the Sec or Tat translocon in Gram-negative (diderm) bacteria [1,2]. The T2SG family includes proteins such as EpsG (P45773) in Vibrio cholera, XcpT also called PddA (Q00514) in Pseudomonas aeruginosa or PulG (P15746)in Klebsiella pneumoniae. The PulG is thought to be anchored in the inner membrane with its C-terminus directed towards the periplasme [3]. Together with other members of the Type II secretion machinery, it is thought to assemble into a pilus-like structure that may function as a dynamic mechanism to push secreted proteins out of the cell. The polypeptide is organized into a long N-terminal alpha-helix followed by a loop region that separates it from a C-terminal anti-parallel beta-sheet [1]. [1]. 15491357. Structure and assembly of the pseudopilin PulG. Kohler R, Schafer K, Muller S, Vignon G, Diederichs K, Philippsen A, Ringler P, Pugsley AP, Engel A, Welte W;. Mol Microbiol 2004;54:647-664. [2]. 1588814. Protein secretion in Pseudomonas aeruginosa: characterization of seven xcp genes and processing of secretory apparatus components by prepilin peptidase. Bally M, Filloux A, Akrim M, Ball G, Lazdunski A, Tommassen J;. Mol Microbiol 1992;6:1121-1131. [3]. 2129543. Five additional genes in the pulC-O operon of the gram-negative bacterium Klebsiella oxytoca UNF5023 which are required for pullulanase secretion. Reyss I, Pugsley AP;. Mol Gen Genet 1990;222:176-184. [4]. 15223057. The general secretory pathway: a general misnomer?. Des. TRUNCATED at 1650 bytes (from Pfam)

Date:

2024-10-16

This short motif directs methylation of the conserved phenylalanine residue. It is most often found at the N-terminus of pilins and other proteins involved in secretion, see Pfam:PF00114, Pfam:PF05946, Pfam:PF02501 and Pfam:PF07596. (from Pfam)

Date:

2024-08-14

GspG is the major pseudopilin of type II secretion systems (T2SS). The system previously was known as the main terminal branch of the general secretion pathway, hence the gene symbol.

Gene:

gspG

Date:

2021-05-12

type II secretion system protein GspG is involved in a type II secretion system (T2SS, formerly general secretion pathway, GSP) for the export of proteins; required for the translocation of a variety of enzymes across the outer membrane

Date:

2023-03-01

This model describes many but not all examples of the N-terminal region of bacterial proteins that resemble type IV pilins at their N-terminus, with a cleavage site G^FxxxE followed by a hydrophobic stretch. The new N-terminal residue, usually Phe, is methylated. Separate domains of the prepilin peptidase appear responsible for cleavage and methylation. Proteins with this N-terminal region include type IV pilins and other components of pilus biogenesis, competence proteins, and type II secretion proteins. Typically several proteins in a single operon have this N-terminal domain. The N-terminal cleavage and methylation site is described by PROSITE motif PS00409 as [KRHEQSTAG]-G-[FYLIVM]-[ST]-[LT]-[LIVP]-E-[LIVMFWSTAG](14).

Date:

2019-09-10