Blasting an unknown protein with a predicted pattern

[ahmadkhalifa]

Hello,

I want to blast a certain pattern that I think exist in my protein. I know the organism where the protein is expressed, but I don't know the identity or the sequence of the protein. I also have an idea about the total length of the protein and where my pattern of interest might lie.

I looked into phi-blast but it requires that I provide a sequence! Can I provide a sequence made up of wild cards corresponding to the length of my protein? How to restrict the pattern searching to a certain location in the sequence?