Key points are not available for this paper at this time.
The PROSITE database (http://www.expasy.ch/sprot/prosite.htm l) consists of biologically significant patterns and profiles formulated in such a way that with appropriate computational tools it can help to determine to which known family of protein (if any) a new sequence belongs, or which known domain(s) it contains.
Hofmann et al. (Fri,) studied this question.