C terminus

A tetrapeptide (such as Val - Gly - Ser - Ala ) with
green marked N-terminal α-amino acid (in the example: L- valine ) and blue marked C-terminal α-amino acid (in the example: L -alanine ).

The C-terminus or carboxy-terminus denotes that end of a protein or polypeptide which has an amino acid with a free carboxy group (COOH).

Protein biosynthesis on the ribosome ends at the C terminus, the last amino acid being determined by the last amino acid- coding triplet of the mRNA before that of the stop codon . The protein thus has a distinguishable beginning and an end. The peptide bond , in which a carboxy group is always linked to an α- amino group of the next amino acid, leaves an amino group free at the beginning of a protein and a carboxy group at the end.

Consequently, the end of the molecule of a peptide opposite the C terminus is called the N terminus or amino terminus .

literature

• Jeremy M. Berg, John L. Tymoczko, Lubert Stryer: Biochemistry. 6 edition, Spektrum Akademischer Verlag, Heidelberg 2007. ISBN 978-3-8274-1800-5 .
• Donald Voet, Judith G. Voet: Biochemistry. 3rd edition, John Wiley & Sons, New York 2004. ISBN 0-471-19350-X .

Individual evidence

1. ^ Brockhaus ABC Chemie , VEB FA Brockhaus Verlag Leipzig 1965, pp. 1031-1033.