Lectin-like sequences in genome of Borrelia burgdorferi

Using degenerative primers designed on the basis of known sequences of lectin genes from different sources a fragment of genomic DNA of Borrelia burgdorferi (strain B31) that contained a lectin-like sequence was isolated, cloned and sequenced. The presence of an open reading frame of 268 amino acids (position 1501-2304 bp) and the computer analysis of the predicted amino acid sequence showed 37% of identity and 75% of homology over region of 25 amino acids with the legume lectin proteins, including erythroagglutinating phytohemagglutinin (PHA-E) and leucoagglutinating phytohemagglutinin (PHA-L). The further analysis of the predicted amino acid sequence showed the presence of another two domains (positions 198-211 and 215-226 aa) consisting of the characteristic conserved sequence motifs for legume lectin proteins. Hemagglutinating activity was detected in lysate of B. burgdorferi (strain B31) spirochete and the affinity to fetuin was determined in a hemagglutination inhibition test. Hemagglutinating activity was also found in a crude lysate of the recombinant clones carrying the fragment of B. burgdorferi genomic DNA. The inhibition of agglutinating activity by fetuin, D-galactosamine and D-mannosamine was determined using the standard procedure of hemagglutination inhibition test with native rabbit red blood cells (RBC).