New Family of Ulvan Lyases Identified in Three Isolates from the Alteromonadales Order
| Autor: | Vitaliy Buravenkov, Ehud Banin, Asael Herman, William Helbert, Moran Kopel, Yana Belnik |
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| Rok vydání: | 2016 |
| Předmět: |
0301 basic medicine
Rhamnose Context (language use) Uronic acid Alteromonadaceae medicine.disease_cause Biochemistry Microbiology Cell wall 03 medical and health sciences chemistry.chemical_compound Polysaccharides Alteromonadales medicine Glycoside hydrolase Molecular Biology Escherichia coli Polysaccharide-Lyases biology Cell Biology biology.organism_classification Up-Regulation Kinetics 030104 developmental biology chemistry Enzymology Genome Bacterial |
| Zdroj: | Journal of Biological Chemistry. 291:5871-5878 |
| ISSN: | 0021-9258 |
| Popis: | Ulvan is the main polysaccharide component of the Ulvales (green seaweed) cell wall. It is composed of disaccharide building blocks comprising 3-sulfated rhamnose linked to d-glucuronic acid (GlcUA), l-iduronic acid (IdoUA), or d-xylose (Xyl). The degradation of ulvan requires ulvan lyase, which catalyzes the endolytic cleavage of the glycoside bond between 3-sulfated rhamnose and uronic acid according to a β-elimination mechanism. The first characterized ulvan lyase was identified in Nonlabens ulvanivorans, an ulvanolytic bacterial isolate. In the current study, we have identified and biochemically characterized novel ulvan lyases from three Alteromonadales isolated bacteria. Two homologous ulvan lyases (long and short) were found in each of the bacterial genomes. The protein sequences have no homology to the previously reported ulvan lyases and therefore are the first representatives of a new family of polysaccharide lyases. The enzymes were heterologously expressed in Escherichia coli to determine their mode of action. The heterologous expressed enzymes were secreted into the milieu subsequent to their signal sequence cleavage. An endolytic mode of action was observed and studied using gel permeation chromatography and (1)H NMR. In contrast to N. ulvanivorans ulvan lyase, cleavage occurred specifically at the GlcUA residues. In light of the genomic context and modular structure of the ulvan lyase families identified to date, we propose that two ulvan degradation pathways evolved independently. |
| Databáze: | OpenAIRE |
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