2.1.1.300 | S-adenosyl-L-methionine + (S)-tetrahydropapaverine |
i.e. THP, low activity, a racemic mixture of THP is converted by PavNMT to laudanosine. The benzyl group of (S)-THP is most deeply buried in the substrate-binding pocket, whereas the isoquinoline moiety lies in a more exposed position where the plane of the six-carbon ring is stacked in a parallel arrangement against the benzyl group of a molecule of (R)-THP. The molecule of (R)-THP appears to be bound more loosely, with fewer direct contacts with the protein than seen for the molecule of (S)-THP. The loop formed by residues 75-91 covers both THP molecules, and the structure of this loop appears to be dependent on the binding of both THP molecules, because it is disordered when THP is not bound |
Thalictrum flavum subsp. glaucum |
S-adenosyl-L-homocysteine + (S)-laudanosine |
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