Undecaprenyl-phosphate 4-deoxy-4-formamido-L-arabinose transferase (, undecaprenyl-phosphate Ara4FN transferase, Ara4FN transferase, polymyxin resistance protein PmrF, ') is an enzyme with systematic name '. This enzyme catalyses the following chemical reaction
The enzyme shows no activity with UDP-4-amino-4-deoxy-beta-L-arabinose.