Ceramidase: Difference between revisions

CerN consists of two domains: a catalytic domain near the N-terminal and an immunoglobulin-fold domain near the C-terminal.<ref name="Inoue">PMID:19088069</ref> Three β-sheets, each formed from four β-strands, compose a β-prism fold at the center of the N-terminal domain.<ref name="Inoue">PMID:19088069</ref> Surrounding the β-prism fold are 11 α-helices, forming an <scene name='91/910024/Bprism/3'>α+ β 2-layer sandwich fold</scene>.<ref name="Inoue">PMID:19088069</ref> The immunoglobulin-like C-terminal domain is composed of two β-sheets, containing four β-strands each, forming a <scene name='91/910024/Igfold/1'>β-sandwich fold</scene>.<ref name="Inoue">PMID:19088069</ref> Between the N- and C-terminal domains is a magnesium/calcium ion binding site that links together the two domains.<ref name="Inoue">PMID:19088069</ref> His37, Asp579, Asp581, and Thr854 interact with divalent cations within the <scene name='91/910024/Mg_bs/1'>magnesium/calcium ion binding site</scene>.<ref name="Inoue">PMID:19088069</ref> A <scene name='91/910024/Zinc_bs/3'>second metal-binding site containing a zinc ion</scene> is located within the N-terminal domain active site, where it is coordinated by His97, His204, Glu411, and a water molecule.<ref name="Inoue">PMID:19088069</ref>