S-layer
S-layer is a part of the cell envelope found in almost all archaea, as well as in many types of bacteria. The S-layer is directly attached to the outermost part of the cell, and it provides a rigid but flexible covering over the entire cell surface. This layer is composed of a single type of protein or glycoprotein that self-assembles into a two-dimensional crystalline lattice.
Structure[edit | edit source]
The S-layer is typically 5-25 nm thick, with a pore size of 2-8 nm. The individual proteins or glycoproteins are typically 40-200 kDa in size, and they form a lattice with a unit cell of 3-30 nm. The lattice can be oblique (p1, p2), square (p4), or hexagonal (p3, p6) in symmetry.
Function[edit | edit source]
The S-layer provides a protective coat to the cell and can act as a barrier against large molecules and ions. It also plays a role in cell adhesion and surface recognition. In some bacteria, the S-layer is involved in pathogenicity.
S-layer in Archaea[edit | edit source]
In archaea, the S-layer is the only component of the cell wall and it is composed of proteins or glycoproteins. The S-layer in archaea is attached to the plasma membrane via lipid anchors.
S-layer in Bacteria[edit | edit source]
In bacteria, the S-layer is attached to the peptidoglycan layer by secondary cell wall polymers. In some bacteria, the S-layer is associated with the outer membrane.
See also[edit | edit source]
References[edit | edit source]
S-layer Resources | ||
---|---|---|
|
|
Translate to: East Asian
中文,
日本,
한국어,
South Asian
हिन्दी,
Urdu,
বাংলা,
తెలుగు,
தமிழ்,
ಕನ್ನಡ,
Southeast Asian
Indonesian,
Vietnamese,
Thai,
မြန်မာဘာသာ,
European
español,
Deutsch,
français,
русский,
português do Brasil,
Italian,
polski
Navigation: Wellness - Encyclopedia - Health topics - Disease Index - Drugs - World Directory - Gray's Anatomy - Keto diet - Recipes
Search WikiMD
Ad.Tired of being Overweight? Try W8MD's physician weight loss program.
Semaglutide (Ozempic / Wegovy and Tirzepatide (Mounjaro) available.
Advertise on WikiMD
WikiMD is not a substitute for professional medical advice. See full disclaimer.
Credits:Most images are courtesy of Wikimedia commons, and templates Wikipedia, licensed under CC BY SA or similar.Contributors: Admin, Prab R. Tumpati, MD