The protein encoded by this gene is a dehydratase that converts trans-3-hydroxy-L-proline to delta(1)-pyrroline-2-carboxylate. This enzyme may function to degrade dietary proteins that contain trans-3-hydroxy-L-proline as well as other proteins such as collagen IV. The encoded protein can be converted to an epimerase by changing a threonine to a cysteine at a catalytic site. [provided by RefSeq, Sep 2016],