User:Marvin O'Neal/VlsE: Difference between revisions

Variable Major Protein (VMP)-like sequence Expressed ('''VlsE''') is a surface lipoprotein of ''Borrelia burgdorferi'', the causative agent of [http://en.wikipedia.org/wiki/Lyme_disease Lyme Disease].  It undergoes [http://en.wikipedia.org/wiki/Antigenic_variation antigenic variation] seemingly important in evasion of the host’s immune system.  In addition, the protein is used for Lyme disease diagnosis.  It is composed of four similar subunits each possessing two invariable domains and one variable domain.<ref name="A">PMID:10569796</ref>  The variable domain contains six variable regions (VR₁-VR₆), and six invariable regions (IR₁-IR₆).  Research suggests that the protein may exist as a dimer where each monomeric C & N termini neighbor each other forming the membrane proximal portion of the protein, and the variable regions form the membrane distal portion.<ref name="B">PMID:11923306</ref> <ref name="C">PMID:11716485</ref>    The invariable regions are largely embedded in the protein and remain relatively unchanged within the host and across strains.  The variable regions encompass 37% of the VlsE’s exposed surface area despite comprising only 25% of the protein.<ref name="A" /> <ref name="B" />  However, 50% of the VR surface area is exposed while IR₆, the immunodominant portion, exposes just 13.7% of its surface area.  This leaves only <scene name='Studio:G5SecL01/Ir_6_4_residues/1'>four amino residues</scene> of the antigenic IR₆ unprotected: lysine-276, glutamine-279, lysine-291, and lysine-294.  Thus, it is almost entirely embedded in the protein and <scene name='Studio:G5SecL01/Ir6_embedded/1'>sheilded by the variable regions </scene>.<ref name="B" /> <br>