The present invention relates to protease variants and methods for obtaining protease variants. The present invention also relates to polynucleotides encoding the variants; nucleic acid constructs, vectors, and host cells comprising the polynucleotides; and methods of using the variants.

Disclosed herein are methods that may be used for the synthesis of benzylisoquinoline alkaloids (BIAs) such as alkaloid morphinan. The methods disclosed can be used to produce thebaine, oripavine, codeine, morphine, oxycodone, hydrocodone, oxymorphone, hydromorphone, naltrexone, naloxone, hydroxycodeinone, neopinone, and/or buprenorphine. Compositions and organisms useful for the synthesis of BIAs, including thebaine synthesis polypeptides, purine permeases, and polynucleotides encoding the same, are provided.