The present invention is directed to phenylalanine ammonia-lyase (PAL)
produced by prokaryotes, wherein such prokaryotic PAL wherein the PAL
variant has a greater phenylalanine-converting activity and/or a reduced
immunogenicity as compared to a wild-type PAL. The invention thus
provides compositions of bacterial PAL and biologically active fragments,
mutants, variants and analogs thereof, as well as methods for the
production, purification, and use of such compositions for therapeutic
and industrial purposes.