MIMM 214 Lecture Notes - Lecture 12: Transmembrane Protein, Signal 1, Thymus
4 Feb 2017
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Document Summary
Transmembrane glycoproteins that present antigenic peptides to t cells. Each chain of the mhc has several ig-like domains. A modular secondary structure shared among many molecules of the immune system. Mhc i only alpha chain with three domains interacting with a single beta2-microglobulin. Mhc ii two transmembrane proteins (alpha and beta) each of which has two immunoglobulin-like domains. They assemble into a similar quaternary structure. It has a barrel-like structure formed of 2 beta sheets linked by a disulfide bridge: an allele-specific ag peptide-binding cleft or groove facing outwards highest level of variance, a more conserved are facing the cell membrane. Peptide binding groove of both mhc i and ii have alpha helices and beta pleated sheets. We can see where the disulfide bonds are in the image to the right they help create the 3d structure in both structures. We can also easily see the differences in the transmembrane domains of mhc i and ii.
