FASTA file format

Crux searches protein sequence databases given in FASTA format. The format is very simple. Every entry consists of a sequence identifier (ID), an optional comment (COMMENT), and a sequence (SEQUENCE). The format looks like this:


The special character ">" marks the beginning of a new sequence. The ">" character is followed immediately by the sequence identifier. The rest of that line is occupied by the optional comment. Subsequent lines contain the sequence itself.

Some rules about representing sequences:

Here is an example of three sequences in FASTA format.