Identification and characterization of 2-oxoglutarate-dependent dioxygenases catalyzing selective cis-hydroxylation of proline and pipecolinic acid from actinomycetes

Microbial hydroxylases were screened for the capacity to effect direct hydroxylation of proline and pipecolinic acid, based on genomic information. Of the eight candidates screened, 2-oxoglutarate-dependent hydroxylase from Streptosporangium roseum NBRC 3776T and aspartyl/asparaginyl β-hydroxylase from Catenulispora acidiphila NBRC 102108T showed both proline and pipecolinic acid hydroxylation activities. In the case of l-proline hydroxylation, both enzymes catalyzed the simultaneous formation of cis-3-hydroxy-l-proline and cis-4-hydroxy-l-proline, and cis-4-hydroxy-l-proline was preferentially produced. In the case of l-pipecolinic acid hydroxylation, both enzymes catalyzed the simultaneous formation of cis-3-hydroxy-l-pipecolinic acid and cis-5-hydroxy-l-pipecolinic acid. While the former enzyme preferentially produced cis-3-hydroxy-l-pipecolinic acid, the latter enzyme preferentially produced cis-5-hydroxy-l-pipecolinic acid.