What is the “CDS” feature key in a “Sequence Listing XML”?

This page is an FAQ based on guidance from the Manual of Patent Examining Procedure. It is provided as guidance, with links to the ground truth sources. This is information only: it is not legal advice.

The “CDS” (Coding Sequence) feature key in a “Sequence Listing XML” is used to identify coding sequences, which are sequences of nucleotides corresponding to the sequence of amino acids in a protein. As explained in MPEP 2413.01(g):

“The ‘CDS’ feature key may be used to identify coding sequences, i.e., sequences of nucleotides which correspond to the sequence of amino acids in a protein and the stop codon. The location of the ‘CDS’ feature in the mandatory element INSDFeature_location must include the stop codon.”

The “CDS” feature key is often used with qualifiers such as “transl_table” and “translation” to provide additional information about the coding sequence and its translation. The encoded amino acid sequence must be included in the sequence listing with its own sequence identifier, referenced by the “protein_id” qualifier.