Explaining the effect of an nsSNP using a homology model based on a MCSG structure. The interaction between S-adenosyl methionine (SAM) and mitochondrial tRNA-specific 2-thiouridylase 1. The Ala10Ser variant probably introduces a hydrogen bond between SAM and the enzyme that increases binding affinity and thus slows down SAM release hence reducing activity. The wild type model is shown in red and the Ala10Ser variant is shown in blue. The variant residue and SAM are coloured according to their atom types and potential hydrogen bonds are shown in yellow.