[Contribution of lectin sugar-binding peptides structure determines specificity of rhizobium-legume symbiosis in Galega orientalis and G. officinalis].

A significant heterogeneity between bacteria Rhizobium galegae bv. officinalis and R. galegae bv. orientalis forming the nitrogen-fixing symbiosis with Galega officinalis and G. orientalis, respectively, and not forming any single cross-inoculation group, was found by means of RAPD and RFEL methods. The high level of sequence similiraty between lectins of these plants indicates at their close relationship. However the sequences of lectin sugar binding peptides (SBP) of G. orientalis (TYCNPGWDPRDR) and G. officinalis (TFYNEEWDLVIKDEH) were highly diverged. Amino acids of SBP which are involved in linkage of Ca2+ and Mn2+ ions responsible for stabilization of spatial structure of carbohydrate-binding "pocket", keep their position in peptide. It suggests that lectins participate in Rhizobium-legume symbiosis and that carbohydrate-binding site plays a key role in this process.