Search results
Results From The WOW.Com Content Network
A pilus (Latin for 'hair'; pl.: pili) is a hair-like cell-surface appendage found on many bacteria and archaea. [1] The terms pilus and fimbria (Latin for 'fringe'; plural: fimbriae ) can be used interchangeably, although some researchers reserve the term pilus for the appendage required for bacterial conjugation .
LPXTG Pili in Gram-positive bacteria contain spontaneously formed isopeptide bonds. These bonds provide enhanced mechanical [12] and proteolytic [13] stability to the pilin protein. Recently, the pilin protein from Streptococcus pyogenes has been split into two fragments to develop a new molecular tool called the isopeptag. [14]
Type IV secretion systems are a highly versatile group, present in Gram positive bacteria, Gram negative bacteria, and archaea. They usually involve a single step which utilizes a pilus, though exceptions exist. [3] Type IV secretion systems are highly diverse, with a variety of functions and types due to different evolutionary paths.
Both gram-positive and gram-negative bacteria commonly have a surface layer called an S-layer. In gram-positive bacteria, the S-layer is attached to the peptidoglycan layer. Gram-negative bacteria's S-layer is attached directly to the outer membrane. Specific to gram-positive bacteria is the presence of teichoic acids in the cell wall. Some of ...
The cell wall of some Gram-positive bacteria can be completely dissolved by lysozymes which attack the bonds between N-acetylmuramic acid and N-acetylglucosamine. In other Gram-positive bacteria, such as Staphylococcus aureus, the walls are resistant to the action of lysozymes. [4] They have O-acetyl groups on carbon-6 of some muramic acid ...
Twitching motility is a form of crawling bacterial motility used to move over surfaces. Twitching is mediated by the activity of hair-like filaments called type IV pili which extend from the cell's exterior, bind to surrounding solid substrates, and retract, pulling the cell forwards in a manner similar to the action of a grappling hook.
Sortase refers to a group of prokaryotic enzymes that modify surface proteins by recognizing and cleaving a carboxyl-terminal sorting signal.For most substrates of sortase enzymes, the recognition signal consists of the motif LPXTG (Leu-Pro-any-Thr-Gly), then a highly hydrophobic transmembrane sequence, followed by a cluster of basic residues such as arginine.
Lipid II is a precursor molecule in the synthesis of the cell wall of bacteria. It is a peptidoglycan, which is amphipathic and named for its bactoprenol hydrocarbon chain, which acts as a lipid anchor, embedding itself in the bacterial cell membrane. Lipid II must translocate across the cell membrane to deliver and incorporate its disaccharide ...