LMP299Y1 Lecture Notes - Anthrax Toxin, Antxr2, Ion
6 May 2014
School
Department
Course
Professor
Document Summary
Pa - antxr - pa20 and pa63 - ef/lf. Pa binding restored by antxr1 cdna to cho-r1. 1 cdna also restores toxin sensitivity. Both are ubiquitously expressed, bind extracellular components, and are type i membrane proteins. I domain present in both - aka vwa domain. Antxr2-/- in macrophages - resistant to toxin, suggesting macrophages only express antxr2. Myeloid-only antxr2-/2 in mice - resistant to infection; sensitive to toxins ef and lf. Complete loss of antxr2 in mice - resistant to ef and lf. Pa binds the i domain of antxr1/2 with divalent cation between. D683 is an amino acid in pa; aspartic acid that binds directly to divalent cation; if mutate d683, I domain: open conformation - c terminal alpha helix down, closed conformation - c terminal alpha helix up. Phenylalanine ring moves along with alpha helix. Alpha helix shifting changes affinity for ligand.
