As part of the E1 complex, the pyrophosphate ester of this molecule attacks pyruvate via a lone pair on its (*) thiazole group in the first step of acetyl-CoA synthesis.
The first step in this molecule's regeneration is catalyzed by aminopyrimidine aminohydrolase, yielding a amino-hydroxymethylpyrimidine as one product. A form of this molecule is the substrate of the only known eukaryotic riboswitch; that riboswitch alters the length of the 3-prime UTR. As part of the E1 complex, the pyrophosphate ester of this molecule attacks pyruvate via a lone pair on its (*) thiazole group in the first step of acetyl-CoA synthesis. Arsenic poisoning has the same effect as a deficiency of this molecule, which has symptoms like cardiac enlargement and weakining of the capillaries. Those symptoms are the "wet" form of a certain disease that can be cured by eating rice bran, which is rich in this compound. For 10 points, name this sulfur-containing B vitamin, a deficiency of which causes beriberi.
The first step in this molecule's regeneration is catalyzed by aminopyrimidine aminohydrolase, yielding a amino-hydroxymethylpyrimidine as one product.
thiamine [or vitamin B1; do not accept "thymine"]