Cytosolic Sulfotransferase 4A1/SULT4A1: Proteins and Enzymes

Cytosolic SULT4A1 (Sulfotransferase 4A1 also BR-STL1/Brain sulfotransferase-like protein) is a 33-36 kDa member of the sulfotransferase 4 family of enzymes. SULT4A1 message is widely expressed. However, it appears to be translated only in brain. SULT4A is very unusual in that it is the only SULT that shows minimal activity on synthetic laboratory substrates. Instead, it acts on catecholamines and T4 in a manner that may not involve sulfonation. Human SULT4A1 is 284 amino acids (aa) in length. A weak PAPS binding site is found between aa 246-254. There are two potential isoforms, one that shows a 13 aa substitution for aa 248-284, and a second that contains a 48 aa substitution for aa 202-247. Full length human SULT4A1 is 98% aa identical to mouse SULT4A1.