5M42:
reference: Proline dehydrogenase from Thermus thermophilus does not discriminate between FAD and FMN as cofactor., Huijbers MM, Martinez-Julvez M, Westphal AH, Delgado-Arciniega E, Medina M, van Berkel WJ, Sci Rep. 2017 Mar 3;7:43880. doi: 10.1038/srep43880. PMID: 28256579

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