Generation of Ligand Specificity and Modes of Oligomerization in beta-Prism I Fold Lectins

Chandran, Thyageshwar and Sharma, Alok and Vijayan, Mamannamana (2013) Generation of Ligand Specificity and Modes of Oligomerization in beta-Prism I Fold Lectins. [Book Chapter]

PDF gen_lig_vijayan_2013.pdf - Published Version Restricted to Registered users only Download (6MB) | Request a copy

Abstract

beta-Prism I fold lectins constitute one of the five widely occurring structural classes of plant lectins. Each single domain subunit is made up of three Greek key motifs arranged in a threefold symmetric fashion. The threefold symmetry is not reflected in the sequence except in the case of the lectin from banana, a monocot, which carries two sugar-binding sites instead of the one in other lectins of known three-dimensional structure, all from dicots. This is believed to be a consequence of the different evolutionary paths followed by the lectin in monocots and dicots. The galactose-specific lectins among them have two chains produced by posttranslational proteolysis and contain three aromatic residues at the binding site. The extended binding sites of galactose- and mannose-specific lectins have been thoroughly characterized. Ligand binding at the sites involves both conformational selection and induced fit. Molecular plasticity of some of the lectins in the family has been characterized. The plasticity appears to be such as to promote variability in quaternary association which could be dimeric, tetrameric, or octameric. Structural and evolutionary reasons for the variability have been explored, and the relation of oligomerization to ligand binding and conformational selection investigated.

Item Type:	Book Chapter
Series.:	Advances in Protein Chemistry and Structural Biology
Publisher:	ELSEVIER ACADEMIC PRESS INC
Additional Information:	Copyright for this article belongs to Science Direct
Department/Centre:	Division of Biological Sciences > Molecular Biophysics Unit
Date Deposited:	21 Oct 2013 05:25
Last Modified:	28 Oct 2013 05:06
URI:	http://eprints.iisc.ac.in/id/eprint/47530

Actions (login required)

View Item