Proteolytic Processing, Maturation, and Unique Synteny of Streptomyces Hemagglutinin, SHA

Blood-type B specific hemagglutinin (L-rham/D-gal-specific lectin) secreted by Streptomyces sp. 27S5 (SHA) was purified over 40 years ago. Despite the loss of original strain and lack genomic information, amino acid sequence its SHA recently determined based on peptides matching to a hypothetical protein S. lavendulae, differing only single acid, A108E (J Biol Chem 293:368, 2018). Recombinant (rSHA A108E) exhibited binding L-rham Lactobacillus casei (Shirota) blood type B-specificity, supporting notion that rSHA is equivalent authentic SHA. To address questions how biosynthesized lost as well what biological roles may have, we needed identify SHA-secreting strains are identical or at least comparable strain. We took advantage IMC's collection 40,000 actinomycete strains. Out 5,000 with available 16S rRNA gene signatures, 67 shared significant homology were examined. found 17 lavendulae-related homologues in cultures. Seven homogeneity gum arabic affinity chromatography. All pro-SHA proteins having larger masses than archived Proteolytic processing pro-SHAs occurred during after purification, which indicated associated proteases apparently converted into mature SHAs molecular similar Pro-SHAs did not exhibit hemagglutination (HA) activity, but bound gels, suggesting have one active glycan site. The processed appear possess HA activities Comparison strain-specific sequences revealed phylogenetic inconsistencies, cannot be explained deletion horizontal transmission repeated this phylogenic group alone. Genome analysis 1,234 from database resulted discovery 18 encoding genes. Of those, 15 newly identified 16 unique syntenic region encodes gene, limited propagation course evolution. In short, succeeded purifying seven 27S5, however, exceptional, because it expressed form levels 4 times higher those two best-SHA homologue-producing Apart structural functional studies homologous proteins, study led an intriguing discovery, i.e., identification regions. It plausible would play role unknown function achieved ensemble accompanying genes synteny.