Single-pass membrane protein
(Redirected from
Single-pass transmembrane protein
)A single-pass membrane protein also known as single-spanning protein or bitopic protein is a
respiratory chain. A 2013 estimate identified about 1300 single-pass membrane proteins in the human genome.[4]
Topology-based classification
Bitopic proteins are classified into 4 types, depending on their
Uniprot
:
- Type I: N-terminus on the extracellular side of the membrane; removed signal peptide[5]
- Type II: N-terminus on the cytoplasmic side of the membrane; transmembrane helix located close to the N-terminus, where it works as an anchor[6]
- Type III: N-terminus on the extracellular side of the membrane; no signal peptide[7]
- Type IV: N-terminus on the cytoplasmic side of the membrane; transmembrane helix located close to the C-terminus, where it works as an anchor[8]
Hence type I proteins are anchored to the lipid membrane with a stop-transfer anchor sequence and have their N-terminal domains targeted to the ER lumen during synthesis. Type II and III are anchored with a signal-anchor sequence, with type II being targeted to the ER lumen with its C-terminal domain, while type III have their N-terminal domains targeted to the ER lumen.
Structure
A single-pass transmembrane protein typically consists of three domains, the
disorder.[9] Some proteins in this class function as monomers, but dimerization or higher-order oligomerization is common.[9][10]
Evolution
The number of single-pass transmembrane proteins in an organism's
mammalian lineages.[4]
Databases
- Membranome database is a database of bitopic proteins from several model organisms.
- Bitopic proteins in OPM database
References
- ^ "Single-pass membrane protein". www.uniprot.org.
- ^ Membrane Structural Biology: With Biochemical and Biophysical Foundations, by Mary Luckey, 2014, Cambridge University Press, page 91.
- PMID 17258687.
- ^ .
- ^ "Single-pass type I membrane protein". UniProt. Retrieved 15 June 2021.
- ^ "Single-pass type II membrane protein". UniProt. Retrieved 15 June 2021.
- ^ "Single-pass type III membrane protein". UniProt. Retrieved 15 June 2021.
- ^ "Single-pass type IV membrane protein". UniProt. Retrieved 15 June 2021.
- ^ .
- PMC 5487282.
- .