Transmembrane domain

Transmembrane domain

Transmembrane domain usually denotes a single transmembrane alpha helix of a transmembrane protein. It is called a "domain" because an alpha-helix in a membrane can be folded independently from the rest of the protein, similar to domains of water-soluble proteins. More broadly, a transmembrane domain is any three-dimensional protein structure which is thermodynamically stable in a membrane. This may be a single alpha helix, a stable complex of several transmembrane alpha helices, a transmembrane beta barrel, a beta-helix of gramicidin A, or any other structure. Transmembrane helices are usually about 20 amino acids in length, although they may be much longer or shorter.

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. 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. Such prediction methods are commonly applied with a limited success.

The Bioinformatics package [ STRAP] provides access to 15 different TM-helix prediction algorithms.

Wikimedia Foundation. 2010.

Игры ⚽ Поможем написать реферат

Look at other dictionaries:

  • Transmembrane domain of ABC transporters — Pfam box Symbol = ABC membrane Name = ABC transporter transmembrane region width = caption = Pfam= PF00664 InterPro= IPR001140 SMART= PROSITE = PDOC00364 SCOP = 1pf4 TCDB = 3.A.1 OPM family= 18 OPM protein= 1pf4 PDB=ABC transporter transmembrane… …   Wikipedia

  • OmpA-like transmembrane domain — Identifiers Symbol OmpA membrane Pfam PF01389 …   Wikipedia

  • Transmembrane receptor — Transmembrane receptors are integral membrane proteins, which reside and operate typically within a cell s plasma membrane, but also in the membranes of some subcellular compartments and organelles. Binding to a signalling molecule or sometimes… …   Wikipedia

  • Transmembrane protein — A transmembrane protein is a protein that spans the entire biological membrane. Transmembrane proteins aggregate and precipitate in water. They require detergents or nonpolar solvents for extraction, although some of them (beta barrels) can be… …   Wikipedia

  • Cystic fibrosis transmembrane conductance regulator — (ATP binding cassette sub family C, member 7) NBD1 of human CFTR complexed with ATP. PDB rendering based on 1xmi …   Wikipedia

  • ATP-binding domain of ABC transporters — Pfam box Symbol = ABC tran Name = width = caption =Multidrug ABC transporter SAV1866, closed state Pfam= PF00005 InterPro= IPR003439 SMART= PROSITE = PDOC00185 SCOP = 1b0u TCDB = 3.A.1 OPM family= 17 OPM protein=2hyd PDB=PDB3|1vplA:29 210… …   Wikipedia

  • SUN domain — SUN (Sad1p, UNC 84) domains are conserved C terminal protein regions a few hundred amino acids long. SUN domains are usually found following a transmembrane domain and a less conserved region of amino acids. Most proteins containing SUN domains… …   Wikipedia

  • PDZ domain — Molecular structure of the PDZ domain included in the human GOPC (Golgi associated PDZ and coiled coil motif containing protein) protein Identifiers Symbol PDZ …   Wikipedia

  • Discoidin domain-containing receptor 2 — Discoidin domain receptor tyrosine kinase 2 Rendering based on PDB 2WUH …   Wikipedia

  • DHHC domain — A depiction of the topology of DHHC family palmitoyltransferases. Transmembrane alpha helices are represented as black tubes. The DHHC domain is shown as a light orange oval. Identifiers Symbol DHHC …   Wikipedia

Share the article and excerpts

Direct link
Do a right-click on the link above
and select “Copy Link”