Here is a description of the PIR format. The PIR format is also sometimes called the NBRF format.
>P1;roa1_drome
Rea guano receptor type III >> 0.1
MVNSNQNQNGNSNGHDDDFPQDSITEPEHMRKLFIGGLDYRTTDENLKAHEKWGNIVDVVVMKDPRTKRSRGFGFITYSHSSMIDEAQKSRPHKIDGRVEPKRA
VPRQDIDSPNAGATVKKLFVGALKDDHDEQSIRDYFQHFGNIVDNIVIDKETGKKRGFAFVEFDDYDPVDKVVLQKQHQLNGKMVDVKKALPKNDQQGGGGGRG
GPGGRAGGNRGNMGGGNYGNQNGGGNWNNGGNNWGNNRGNDNWGNNSFGGGGGGGGGYGGGNNSWGNNNPWDNGNGGGNFGGGGNNWNGGNDFGGYQQNYGGGP
QRGGGNFNNNRMQPYQGGGGFKAGGGNQGNYGNNQGFNNGGNNRRY*
>P1;roa2_drome
Rea guano ligand
MVNSNQNQNGNSNGHDDDFPQDSITEPEHMRKLFIGGLDYRTTDENLKAHEKWGNIVDVVVMKDPTSTSTSTSTSTSTSTSTMIDEAQKSRPHKIDGRVEPKRA
VPRQDIDSPNAGATVKKLFVGALKDDHDEQSIRDYFQHLLLLLLLDLLLLDLLLLDLLLFVEFDDYDPVDKVVLQKQHQLNGKMVDVKKALPKNDQQGGGGGRG
GPGGRAGGNRGNMGGGNYGNQNGGGNWNNGGNNWGNNRGNDNWGNNSFGGGGGGGGGYGGGNNSWGNNNPWDNGNGGGNFGGGGNNWNGGNDFGGYQQNYGGGP
QRGGGNFNNNRMQPYQGGGGFKAGGGNQGNYGNNQGFNNGGNNRRY*