A Broad-Spectrum α-Glucosidase of Glycoside Hydrolase Family 13 from Marinovum sp., a Member of the Roseobacter Clade.

Glycoside hydrolases (GHs) are a diverse group of enzymes that catalyze the hydrolysis of glycosidic bonds. The Carbohydrate-Active enZymes (CAZy) classification organizes GHs into families based on sequence data and function, with fewer than 1% of the predicted proteins characterized biochemically. Consideration of genomic context can provide clues to infer possible enzyme activities for proteins of unknown function.

Remodeling of Carbon Metabolism during Sulfoglycolysis in Escherichia coli.

Sulfoquinovose (SQ) is a major metabolite in the global sulfur cycle produced by nearly all photosynthetic organisms. One of the major pathways involved in the catabolism of SQ in bacteria such as Escherichia coli is a variant of the glycolytic Embden-Meyerhof-Parnas (EMP) pathway termed the sulfoglycolytic EMP (sulfo-EMP) pathway, which leads to the consumption of three of the six carbons of SQ and the excretion of 2,3-dihydroxypropanesulfonate (DHPS). Comparative metabolite profiling of aerobically glucose (Glc)-grown and SQ-grown E.

The sulfoquinovosyl glycerol binding protein SmoF binds and accommodates plant sulfolipids.

Sulfoquinovose (SQ) is the anionic headgroup of the ubiquitous plant sulfolipid, sulfoquinovosyl diacylglycerol (SQDG). SQDG can undergo delipidation to give sulfoquinovosyl glycerol (SQGro) and further glycoside cleavage to give SQ, which can be metabolized through microbial sulfoglycolytic pathways. Exogenous SQDG metabolites are imported into bacteria through membrane spanning transporter proteins.

Genome sequences of Arthrobacter spp. that use a modified sulfoglycolytic Embden-Meyerhof-Parnas pathway.

Sulfoglycolysis pathways enable the breakdown of the sulfosugar sulfoquinovose and environmental recycling of its carbon and sulfur content. The prototypical sulfoglycolytic pathway is a variant of the classical Embden-Meyerhof-Parnas (EMP) pathway that results in formation of 2,3-dihydroxypropanesulfonate and was first described in gram-negative Escherichia coli. We used enrichment cultures to discover new sulfoglycolytic bacteria from Australian soil samples.

Oxidative desulfurization pathway for complete catabolism of sulfoquinovose by bacteria.

Catabolism of sulfoquinovose (SQ; 6-deoxy-6-sulfoglucose), the ubiquitous sulfosugar produced by photosynthetic organisms, is an important component of the biogeochemical carbon and sulfur cycles. Here, we describe a pathway for SQ degradation that involves oxidative desulfurization to release sulfite and enable utilization of the entire carbon skeleton of the sugar to support the growth of the plant pathogen SQ or its glycoside sulfoquinovosyl glycerol are imported into the cell by an ATP-binding cassette transporter system with an associated SQ binding protein. A sulfoquinovosidase hydrolyzes the SQ glycoside and the liberated SQ is acted on by a flavin mononucleotide-dependent sulfoquinovose monooxygenase, in concert with an NADH-dependent flavin reductase, to release sulfite and 6-oxo-glucose.

Molecular Basis of Sulfosugar Selectivity in Sulfoglycolysis.

The sulfosugar sulfoquinovose (SQ) is produced by essentially all photosynthetic organisms on Earth and is metabolized by bacteria through the process of sulfoglycolysis. The sulfoglycolytic Embden-Meyerhof-Parnas pathway metabolizes SQ to produce dihydroxyacetone phosphate and sulfolactaldehyde and is analogous to the classical Embden-Meyerhof-Parnas glycolysis pathway for the metabolism of glucose-6-phosphate, though the former only provides one C3 fragment to central metabolism, with excretion of the other C3 fragment as dihydroxypropanesulfonate. Here, we report a comprehensive structural and biochemical analysis of the three core steps of sulfoglycolysis catalyzed by SQ isomerase, sulfofructose (SF) kinase, and sulfofructose-1-phosphate (SFP) aldolase.

Concise synthesis of sulfoquinovose and sulfoquinovosyl diacylglycerides, and development of a fluorogenic substrate for sulfoquinovosidases.

The sulfolipid sulfoquinovosyl diacylglycerol (SQDG) and its headgroup, the sulfosugar sulfoquinovose (SQ), are estimated to harbour up to half of all organosulfur in the biosphere. SQ is liberated from SQDG and related glycosides by the action of sulfoquinovosidases (SQases). We report a 10-step synthesis of SQDG that we apply to the preparation of saturated and unsaturated lipoforms.

Comprehensive Synthesis of Substrates, Intermediates, and Products of the Sulfoglycolytic Embden-Meyerhoff-Parnas Pathway.

Sulfoglycolysis is a metabolic pathway dedicated to the catabolism of the sulfosugar sulfoquinovose (SQ) into smaller organosulfur fragments. An estimated 10 billion tonnes of SQ fluxes through sulfoglycolysis pathways each year, making it a significant aspect of the biogeochemical sulfur cycle. Delineating the molecular details of sulfoglycolysis requires authentic samples of the various metabolites in these pathways.