Phosphotyrosine-binding domain
Protein domain From Wikipedia, the free encyclopedia
In molecular biology, phosphotyrosine-binding domains are protein domains which bind to phosphotyrosine.
| PTB domain (IRS-1 type) | |||||||||
|---|---|---|---|---|---|---|---|---|---|
 irs-1 ptb domain complexed with a il-4 receptor phosphopeptide, nmr, minimized average structure | |||||||||
| Identifiers | |||||||||
| Symbol | IRS | ||||||||
| Pfam | PF02174 | ||||||||
| InterPro | IPR002404 | ||||||||
| SMART | PTBI | ||||||||
| SCOP2 | 1cli / SCOPe / SUPFAM | ||||||||
| CDD | cd01204 | ||||||||
| |||||||||
The phosphotyrosine-binding domain (PTB, also phosphotyrosine-interaction or PI domain) in the protein tensin tends to be found at the C-terminus. Tensin is a multi-domain protein that binds to actin filaments and functions as a focal-adhesion molecule (focal adhesions are regions of plasma membrane through which cells attach to the extracellular matrix). Human tensin has actin-binding sites, an SH2 (Pfam PF00017) domain and a region similar to the tumour suppressor PTEN.[2] The PTB domain interacts with the cytoplasmic tails of beta integrin by binding to an NPXY motif.[3]
The phosphotyrosine-binding domain of insulin receptor substrate-1 is not related to the phosphotyrosine-binding domain of tensin. Insulin receptor substrate-1 proteins contain both a pleckstrin homology domain and a phosphotyrosine binding (PTB) domain. The PTB domains facilitate interaction with the activated tyrosine-phosphorylated insulin receptor. The PTB domain is situated towards the N terminus. Two arginines in this domain are responsible for hydrogen bonding phosphotyrosine residues on an Ac-LYASSNPApY-NH2 peptide in the juxtamembrane region of the insulin receptor. Further interactions via "bridged" water molecules are coordinated by residues an Asn and a Ser residue.[4] The PTB domain has a compact, 7-stranded beta-sandwich structure, capped by a C-terminal helix. The substrate peptide fits into an L-shaped surface cleft formed from the C-terminal helix and strands 5 and 6.[5]
Human proteins containing these domains
APBA1; APBA2; APBA3; APPL1; EPS8; EPS8L1; EPS8L2; EPS8L3; TENC1; TNS; TNS1; TNS3; TNS4; DOK1; DOK2; DOK3; DOK4; DOK5; DOK6; DOK7; FRS2; FRS3; IRS1; IRS2; IRS4; NOS1AP; TLN1; TLN2
See also
- SH2 domains also bind phosphorylated tyrosines
References
External links
Wikiwand - on
Seamless Wikipedia browsing. On steroids.