Transmembrane domain

Transmembrane domain usually denotes a transmembrane segment of single alpha helix of a transmembrane protein.[1] More broadly, a transmembrane domain is any membrane-spanning protein domain.

Identification of transmembrane helices

Transmembrane helices are visible in structures of membrane proteins determined by X-ray diffraction. They may also be predicted on the basis of hydrophobicity scales. Because the interior of the bilayer and the interiors of most proteins of known structure are hydrophobic, it is presumed to be a requirement of the amino acids that span a membrane that they be hydrophobic as well. However, membrane pumps and ion channels also contain numerous charged and polar residues within the generally non-polar transmembrane segments.

Using hydrophobicity analysis to predict transmembrane helices enables a prediction in turn of the "transmembrane topology" of a protein; i.e. prediction of what parts of it protrude into the cell, what parts protrude out, and how many times the protein chain crosses the membrane.

Examples
gollark: I like at least having italicization work.
gollark: Like the not very intuitive permissions model, needing you to run a bouncer or something if you want message history, and lack of (generally available) text formatting or file uploads.
gollark: IRC has some problematic flaws.
gollark: And is very annoying when I need to plug something in and transfer files.
gollark: I don't actually know which have no data lines, which does sort of defeat the point.

References
  1. Hayley J. Sharpe; Tim J. Stevens; Sean Munro (9 July 2010). "A Comprehensive Comparison of Transmembrane Domains Reveals Organelle-Specific Properties". Cell. 142 (1): 158–169. doi:10.1016/j.cell.2010.05.037. PMC 2928124. PMID 20603021.
This article is issued from Wikipedia. The text is licensed under Creative Commons - Attribution - Sharealike. Additional terms may apply for the media files.