What are fingerprints?

What are fingerprints?

While single motif methods are good at identifying features in a protein, most protein families are characterised not by one, but by several conserved regions, which occur in a certain order. Identifying these regions is the principle behind fingerprints. Fingerprints are composed of multiple short conserved motifs, which are drawn from sequence alignments, as illustrated in Figure 15. Each motif is then converted into an individual profile (as described in the previous section) to create a fingerprint signature.

Figure 15 Representation of the steps involved in creating a fingerprint signature.

Fingerprints are used by the PRINTS database, you can find out more about PRINTS in this book (Attwood. TK, et al. 2006).

What are fingerprints?

Fingerprints are very good at modeling the often small differences between closely related proteins, as illustrated in the example in Figure 16 below.

This means fingerprints can distinguish individual subfamilies within protein families. This allows functional characterisation of sequences at a high level of specificity (identifying individual cellular pathways in which a protein might be involved, the ligand it might bind, the exact reaction it may catalyse, and so on).

 

Figure 16 Multiple sequence alignment showing amino acid conservation across chloride channel protein family members. By using multiple short conserved motifs, fingerprints are able to distinguish closely related subfamilies from each other.