Profile Searching


A profile is a computational representation of sequence properties derived from a family of related proteins. Analogous to single sequences, profiles can be used for database searches using a dynamic programming algorithm. Because profiles allow positionā€specific scoring systems and gap parameters, profile searches offer a greatly increased sensitivity in detecting distant protein relationships.

Keywords: sequence analysis; alignment; evolutionary distance; homology; statistical significance

Figure 1.

Short sample profile, in generalized profile format: (a) small sample alignment of seven sequences with four residues each; (b) generalized profile derived from the alignment in (a). The lines starting with ‘/M’ contain the actual profile data; the other lines contain additional information such as the alphabet used, default gap parameters and normalization parameters.

Figure 2.

Representation of the iterative refinement process.



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Further Reading

Agarwal P and States DJ (1998) Comparative accuracy of methods for protein sequence similarity search. Bioinformatics 14: 40–47.

Attwood TK (2000) The role of pattern databases in sequence analysis. Briefings in Bioinformatics 1: 45–59.

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Vingron M and Waterman MS (1994) Sequence alignment and penalty choice: review of concepts, case studies and implications. Journal of Molecular Biology 235: 1–12.

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How to Cite close
Hofmann, Kay(Sep 2005) Profile Searching. In: eLS. John Wiley & Sons Ltd, Chichester. [doi: 10.1038/npg.els.0005259]