How should circular sequences be represented in a sequence listing?

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.

Circular sequences should be represented as follows:

1. For nucleotide sequences: The applicant must choose the nucleotide in residue position number 1. Numbering is continuous throughout the entire sequence in the 5′ to 3′ direction.
2. For amino acid sequences: When an amino acid sequence is circular and the ring consists solely of amino acid residues linked by peptide bonds, the applicant must choose the amino acid in residue position number 1. Numbering is continuous through the entire sequence in the amino to carboxy direction.

The MPEP states for nucleotide sequences: “When nucleotide sequences are circular in configuration, applicant must choose the nucleotide in residue position number 1. Numbering is continuous throughout the entire sequence in the 5′ to 3′ direction, or in the direction that mimics the 5′ to 3′ direction.“

For amino acid sequences: “When an amino acid sequence is circular in configuration and the ring consists solely of amino acid residues linked by peptide bonds, i.e., the sequence has no amino and carboxy termini, applicant must choose the amino acid in residue position number 1. Numbering is continuous through the entire sequence in the amino to carboxy direction.“