I need coding sequences of eukaryotes. NCBI ftp contains both frn and ffn files. Can you, please, tell me, what is the difference, and what format I should use for the analysis (it should be cDNAs only)
there’s a readme file in each folder. I suggest you read it.
The files are present in the following formats:
*.asn = ASN.1 file, print form, replaces .prt
*.faa = FASTA Amino Acid file
*.ffn = FASTA nucleotide coding regions file
*.fna = FASTA Nucleic Acid file
*.gbk = GenBank flat file format
*.ptt = Protein Table
*.val = ASN.1 binary format
*.tar.Z = unix tar and compressed files (not all files are compressed),
where all of the above files are present. If you want all
files for a group, all you need is to FTP this one file.