A domain is a conserved fraction of a protein that has the ability to form a distinct three-dimensional structure. Domains often have a specific role that they play in the overall function of the protein. It's possible to find an identical domain in an entirely different kind of protein that has an unrelated function. We can then use our knowledge of what the domain is responsible for to help us better understand the other unrelated protein.
PTK7 Domains
PTK7 domains as predicted by Pfam. The pink diamond is there to highlight a predicted active site.
PTK7 domains as predicted by SMART
PTK7 domains as predicted by InterPro
What do these domains do? [2]
Immunoglobulin molecules have a tetramer structure made of two heavy chains and two light chains linked by disulphide bonds. There are four main groups of Ig-like molecules. They are C1-set, C2-set, I-set, and V-set. Ig-like domains are known to serve several functions, but some of the more common roles are in cell-cell recognition, cell-surface receptors, muscle structure, and the immune system. Protein kinases are involved in a plethora of cellular activities including division, proliferation, apoptosis, and differentiation to name a few. These catalytic enzymes are very highly conserved in a wide range of organisms including E. coli and humans. The N-terminal has a stretch of glycines near a lysine residue that plays a role in ATP binding. In the center of the catalytic domain is a highly conserved aspartic acid which is important for the catalytic activity of the enzyme.
Conserved Domains
Conclusion
There were several conserved IGc2 domains, as well as one relatively conserved IG domain. All of the species had a conserved transmembrane region adjacent to the tyrosine kinase catalytic domain, which would indicate that the transmembrane region is necessary for proper function of the catalytic domain. The species most related to humans had a low complexity region next to the transmembrane region. Perhaps the transmembrane region would be an area of interest to study in the future.