The crystallographic structure of phytohemagglutinin-L.

TitleThe crystallographic structure of phytohemagglutinin-L.
Publication TypeJournal Article
Year of Publication1996
AuthorsHamelryck, T. W., M-H. Dao-Thi, F. Poortmans, M. J. Chrispeels, L. Wyns, and R. Loris
JournalJ Biol Chem
Volume271
Issue34
Pagination20479-85
Date Published1996 Aug 23
ISSN0021-9258
KeywordsBinding Sites, Concanavalin A, Crystallography, X-Ray, Models, Molecular, Phytohemagglutinins, Plant Proteins, Prealbumin, Protein Conformation
Abstract

The structure of phytohemagglutinin-L (PHA-L), a leucoagglutinating seed lectin from Phaseolus vulgaris, has been solved with molecular replacement using the coordinates of lentil lectin as model, and refined at a resolution of 2.8 A. The final R-factor of the structure is 20.0%. The quaternary structure of the PHA-L tetramer differs from the structures of the concanavalin A and peanut lectin tetramers, but resembles the structure of the soybean agglutinin tetramer. PHA-L consists of two canonical legume lectin dimers that pack together through the formation of a close contact between two beta-strands. Of the two covalently bound oligosaccharides per monomer, only one GlcNAc residue per monomer is visible in the electron density. In this article we describe the structure of PHA-L, and we discuss the putative position of the high affinity adenine-binding site present in a number of legume lectins. A comparison with transthyretin, a protein that shows a remarkable resemblance to PHA-L, gives further ground to our proposal.

Alternate JournalJ. Biol. Chem.
PubMed ID8702788