The type IV filament superfamily (TFF) is a group of
fibrous protein structures that includes a set of cell projections with evolutionarily related
membrane protein
Membrane proteins are common proteins that are part of, or interact with, biological membranes. Membrane proteins fall into several broad categories depending on their location. Integral membrane proteins are a permanent part of a cell membrane ...
s.
The TFF family seems to have originated in the
last universal common ancestor
The last universal common ancestor (LUCA) is the hypothesized common ancestral cell from which the three domains of life, the Bacteria, the Archaea, and the Eukarya originated. The cell had a lipid bilayer; it possessed the genetic code a ...
, from where it diversified into
archaella,
type IV pili
A pilus (Latin for 'hair'; : pili) is a hair-like cell-surface appendage found on many bacteria and archaea. The terms ''pilus'' and '' fimbria'' (Latin for 'fringe'; plural: ''fimbriae'') can be used interchangeably, although some researchers ...
,
type II secretion system
The type 2 secretion system (often referred to as the type II secretion system or by the initials T2SS) is a type of protein secretion machinery found in various species of Gram-negative bacteria, including many human pathogens such as ''Pseudomo ...
s, and the
Tad pili.
Complexes in the TFF superfamily are unified by the presence of the eponymous type IV
pilin
Pilin refers to a class of fibrous proteins that are found in pilus structures in bacteria. These structures can be used for the exchange of genetic material, or as a cell adhesion mechanism. Although not all bacteria have pili or fimbriae, bact ...
, an
AAA+
AAA, Triple A, or Triple-A is a three-letter initialism or abbreviation which may refer to:
Arts, entertainment, and media
Gaming
* AAA (video game industry) - a category of high budget video games
*'' TripleA'', an open source wargame
Mu ...
ATPase, an integral (cytoplasmic) membrane (IM) platform, and (with the exception of MSH) a
prepilin peptidase.
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]
References
Bacteriology
Protein complexes
{{Membrane-protein-stub