The ribosomal protein P0 of soybean (Glycine max L. Merr.) has antigenic cross-reactivity to soybean seed lectin.
Soybean (Glycine max L. Merr.) mutants lacking the ability to produce the lectin normally found in soybean seeds (SBL) are designated Le-. A protein of higher molecular weight that cross-reacts with antibodies raised to SBL was found at nearly equivalent levels in roots, hypocotyls, and leaves, and at lower levels in cotyledons and dry seeds of both Le+ and Le- soybean cultivars. Earlier work suggested that this protein was a novel lectin. Clones isolated from a Le- soybean root cDNA library produced a cross-reacting protein of the same size in Escherichia coli. Sequence analysis of these clones revealed a high degree of similarity to the ribosomal protein P0. The cross-reacting protein co-purified with ribosomes, and a monoclonal antibody raised to purified brine shrimp P0 cross-reacted to the same protein. The protein showed no lectin activity in a hemagglutination assay, nor did it bind to an N-acetyl-D-galactosamine affinity column. On the basis of this evidence, we conclude that the SBL-cross-reacting protein is not a lectin but a homologue of the ribosomal protein P0. Consequently, Le- soybeans must produce a lectin that is dissimilar to SBL at both the DNA and amino acid levels and we suggest that it is this lectin which is involved in nodulation.
Wycoff
K L
KL
Department of Molecular, Cell and Developmental Biology, University of California, Los Angeles 90095-1606, USA.
van Rhijn
P
P
Hirsch
A M
AM
D000595:Amino Acid Sequence; D001483:Base Sequence; D003001:Cloning, Molecular; D003429:Cross Reactions; D018076:DNA, Complementary / Q000302:isolation & purification; D018506:Gene Expression Regulation, Plant; D037102:Lectins / Q000737:chemistry / Q000235:genetics / Q000276:immunology*; D008969:Molecular Sequence Data; D037121:Plant Lectins; D012269:Ribosomal Proteins / Q000096:biosynthesis / Q000235:genetics / Q000276:immunology*; D012270:Ribosomes / Q000737:chemistry; D012639:Seeds / Q000276:immunology; D030262:Soybean Proteins; D013025:Glycine max / Q000737:chemistry / Q000235:genetics / Q000276:immunology*; D014018:Tissue Distribution; D010835:Phytohemagglutinins
D018076:DNA, Complementary; D037102:Lectins; D037121:Plant Lectins; D012269:Ribosomal Proteins; D030262:Soybean Proteins; C028824:soybean lectin; D010835:Phytohemagglutinins