A Novel Gene Encoding an Enzyme That Degrades a Polysaccharide from the Sheath ofSphaerotilus natans

Study of a novel glycoconjugate, thiopeptidoglycan, and a novel polysaccharide lyase, thiopeptidoglycan lyase

“…By introducing isoelectric focusing, a protein estimated to be 76k (SDS-PAGE) was isolated which exhibited N-terminal amino acid sequence of NH 2 -ATVYEVGPGKTYT. These properties were identical to those of DssA determined earlier [6,7], identifying that a new procedure for DssA isolation was established. The yield of sheath-degrading activity from the crude enzyme by newly developed procedure was 1.7% as summarized in Table 1.…”

“…5a. DssA is already known to act on the deacetylated sheath polysaccharide producing a pentasaccharide [6], but not on the N-acetylated sheath polysaccharide [7]. Based on these evidences, we propose a new systematic name of "thiopeptidoglycan lyase" for DssA.…”

“…These findings revealed that the sheath is formed by the assembly of peptidic glycoconjugate. The glycan can be degraded into pentasaccharide by an enzyme named DssA [6,7], which is secreted by a sheath-utilizing bacterium, Paenibacillus koleovorans [8]. DssA was recognized to be a putative polysaccharide lyase for its action, which cleaves ␣1 → 4 linkage between GalN and GlcA [6,7].…”

Structural determination of the sheath-forming polysaccharide of Sphaerotilus montanus using thiopeptidoglycan lyase which recognizes the 1,4 linkage between α-d-GalN and β-d-GlcA

“…The specificity of thiopeptidoglycan lyase is clearly distinguishable from these known polysaccharide lyases based on its specificity to the linkage between non-N-substituted amino sugar and uronic acid residues. Moreover, no gene exhibiting meaningful similarity to the thiopeptidoglycan lyase gene (dssA, AB084782) at full length was found in our database searches [14]; thiopeptidoglycan lyase does not exhibit significant similarity to known lyase genes at full length.…”

“…For structural determination of the S. montanus sheath, we attempted enzymatic digestion using thiopeptidoglycan lyase (DssA) [5,14,15], which is prepared from Paenibacillus koleovorans [16]. The enzyme can depolymerize the S. natans sheath into its repeating units, enabling complete structural determination of the sheath [5].…”