Sandbox Reserved 345: Difference between revisions

S-Adenosylmethionine decarboxylase is a (αβ)2 <scene name='Sandbox_Reserved_345/Proteins subunits.png'>dimer</scene>, forming a four-layer αββα sandwich <ref name="primary"/>.  The αβ monomers both have the same structure <ref name="primary"/>.  The β chain consists of the residues 1-67 while the α chain contains the residues 68-329 <ref name="four"/>. Each β sheet contains eight anti-parallel β strands <ref name="primary"/>.  AdoMetDC has a very unique fold compared to other large β-sandwich structures as well as other pyruvoyl-dependent amino acid decarboxylases <ref name="primary"/>. The two β sheets are connected by only one covalent bond which allows them a large amount of flexibility to behave as independently folded domains that move with respect to each other <ref name="primary"/>. The α and β subunits are formed by an internal cleavage reaction <ref name="primary"/>.   

AdoMetDC belongs to a small class of decarboxylating enzymes that use as a prosthetic group a covalently bound pyruvate <ref name="primary"/><ref name="two"/>. The same cleavage reaction that forms the α and β subunits also converts a serine (Ser68) residue into the pyruvate <ref name="two"/><ref name="three"/><ref name="six">PMID: 10029540</ref>. This self processing reaction occurs via a N to O acyl rearrangement <ref name="three"/><ref name="four"/>. The pyruvoyl group is bound to the N-terminal of an α subunit <ref name="four"/><ref name="five"/>.