Abstract: The present invention provides a ligand isolated from Moraxella catarrhalis outer membrane protein which binds to CEACAM receptors, said ligand comprising a receptor binding domain comprising an amino acid sequence selected from the group disclosed, or a fragment, homologue, functional equivalent, derivative, degenerate or hydroxylation, sulphonation or glycosylation product or other secondary processing product thereof. The invention also provides medicaments and vaccines comprising said ligand, and their use in the treatment or prophylaxis of infection. Also provided is a screening method for the identification of novel therapeutic compounds.

Abstract: A nucleic acid sequence is provided which encodes a gibberelin 2-oxidase gene which catalyzes the 2&bgr;-oxidation of a gibberelin molecule to introduce a hydroxyl group at C-2 and further catalyzes the oxidation of the hydroxyl group introduced at C-2 to yield the ketone derivative. Such sequences can find application in the preparation of transgenic plants with altered levels of gibberelin 2-oxidase.