Protein
Flavin-dependent tryptophan halogenase PrnA
Organism
Pseudomonas fluorescens
Function
Involved in the biosynthesis of the antifungal antibiotic pyrrolnitrin. Catalyzes the chlorination of tryptophan (Trp) at C7 position to yield 7-chloro-L-tryptophan (7-CLT). The reaction between FADH2, Cl-, and O2 generates the powerful oxidant HOCl, which is presumed to carry out the chlorination reaction. The reaction of HOCl with the active site Lys-79 generates a lysine chloramine, which plays a key role in directing regiospecific chlorination of substrate in this important class of biosynthetic enzymes. It is also able to use bromide ions to generate monobrominated Trp.
Similarity
Belongs to the flavin-dependent halogenase family. Bacterial tryptophan halogenase subfamily.
Sequence
MNKPIKNIVIVGGGTAGWMAASYLVRALQQQANITLIESAAIPRIGVGEATIPSLQKVFFDFLGIPEREWMPQVNGAFKAAIKFVNWRKSPDPSRDDHFYHLFGNVPNCDGVPLTHYWLRKREQGFQQPMEYACYPQPGALDGKLAPCLSDGTRQMSHAWHFDAHLVADFLKRWAVERGVNRVVDEVVDVRLNNRGYISNLLTKEGRTLEADLFIDCSGMRGLLINQALKEPFIDMSDYLLCDSAVASAVPNDDARDGVEPYTSSIAMNSGWTWKIPMLGRFGSGYVFSSHFTSRDQATADFLKLWGLSDNQPLNQIKFRVGRNKRAWVNNCVSIGLSSCFLEPLESTGIYFIYAALYQLVKHFPDTSFDPRLSDAFNAEIVHMFDDCRDFVQAHYFTTSRDDTPFWLANRHDLRLSDAIKEKVQRYKAGLPLTTTSFDDSTYYETFDYEFKNFWLNGNYYCIFAGLGMLPDRSLPLLQHRPESIEKAEAMFASIRREAERLRTSLPTNYDYLRSLRDGDAGLSRGQRGPKLAAQESL