A sequence in FASTA format begins with a single-line description, followed by lines of sequence data. The definition line (defline) is distinguished from the sequence data by a greater-than (>) symbol at the beginning. The word following the ">" symbol is the identifier of the sequence, and the rest of the line is the description (optional). Normally, identifiers are simply protein accession, name or Entrez gi's (e.g., Q5I7T1, AG10B_HUMAN, 129295), but a bar-separated NCBI sequence identifier (e.g., gi|129295) will also be accepted. Any arbitrary user-specified sequence identifier can also be used (e.g., CLONE00073452) but you are advised to use sufficiently long unique words in such case. There should be no space between the ">" and the first letter of the identifier. It is recommended that all lines of text be shorter than 80 characters in length. An example sequence in FASTA format is:
>gi|129295|sp|P01013|OVAX_CHICK GENE X PROTEIN (OVALBUMIN-RELATED) QIKDLLVSSSTDLDTTLVLVNAIYFKGMWKTAFNAEDTREMPFHVTKQESKPVQMMCMNNSFNVATLPAE KMKILELPFASGDLSMLVLLPDEVSDLERIEKTINFEKLTEWTNPNTMEKRRVKVYLPQMKIEEKYNLTS VLMALGMTDLFIPSANLTGISSAESLKISQAVHGAFMELSEDGIEMAGSTGVIEDIKHSPESEQFRADHP FLFLIKHNPTNTIVYFGRYWSP
Blank lines are not allowed in the middle of FASTA input.
Sequences are expected to be represented in the standard IUB/IUPAC amino acid and codes, with these exceptions: lower-case letters are accepted and are mapped into upper-case; U and * are acceptable letters (see below). Before submitting a request, any numerical digits in the query sequence should either be removed or replaced by appropriate letter codes (e.g., X for unknown amino acid residue).
The IUB/IUPAC amino acid codes are:
A alanine P proline B aspartate/asparagine Q glutamine C cystine R arginine D aspartate S serine E glutamate T threonine F phenylalanine U selenocysteine G glycine V valine H histidine W tryptophan I isoleucine Y tyrosine K lysine Z glutamate/glutamine L leucine X any M methionine * translation stop N asparagine - gap of indeterminate lengthNOTE: