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CAS REGISTRY updated with new ambiguity codes

07. December 2006

Current protein sequencing techniques may not distinguish between certain similar amino acid pairs. Due to this problem, the presence of one or the other amino acid is often indicated with a 1- or 3-letter ambiguity code. The amino acids isoleucine and leucine were recently assigned the ambiguity codes "J" and "Xle". New records in REGISTRY can now include these codes.

The REGISTRY Database Summary Sheet is available in STNGuide and on the WEB on our Database List.