Epigenomic revolution in autoimmune diseases

Figure 2 Human wild type spermidine/spermine N1-acetyltransferase. Spermidine/spermine N1-acetyltransferase (SAT1) functions as a dimer with two channels in which the acetylation reaction occurs. A: Top – SAT1 with spermine and acetyl CoA docked in one channel. Bottom – the normal substrates, spermidine and spermine, are shown along with a known inhibitor, BE-3-3-3; B: Top - Close-up of acetyl CoA docked in the channel. Yellow dashes denote hydrogen bonds. The substrate will enter the other end of the channel and bind. Bottom – Spermine and acetyl CoA bind in close proximity in SAT1 so that the acetyl group can transfer to the substrate at which point CoA is released and the acetylspermine has reduced affinity so it releases. Structure of SAT1[38] is 2B4D.pdb from the Protein Data Bank (http://www.rcsb.org).