SEED subsystem annotation using blast

Hi,

I have performed a BLASTP against SEED database (amino acid sequences). I want to annotate the proteins according to the subsystem. I have downloaded the file subsystem2peg from the seed ftp site. when I searched the fig ids assigned during the the blast analysis I could not find them in the file "subsystem2peg". Can anayone suggest me the reason for this and also the procedure for subsystem annotation using SEED blast result.

Thanking you in advance

Surendra