8q58

Publication Abstract from PubMed

Sulfoquinovose (SQ, 6-deoxy-6-sulfoglucose) is a sulfosugar that is the anionic head group of plant, algal and cyanobacterial sulfolipids: sulfoquinovosyl diacylglycerols. SQ is produced within photosynthetic tissues, forms a major terrestrial reservoir of biosulfur, and is an important species within the biogeochemical sulfur cycle. A major pathway for SQ breakdown is the sulfoglycolytic Embden-Meyerhof-Parnas (sulfo-EMP) pathway, which involves cleavage of the 6-carbon chain of the intermediate sulfofructose-1-phosphate (SFP) into dihydroxyacetone and sulfolactaldehyde, catalyzed by class I or II SFP aldolases. While the molecular basis of catalysis is understood for class I SFP aldolases, comparatively little is known about class II SFP aldolases. Here, we report the molecular architecture and biochemical basis of catalysis of two metal-dependent class II SFP aldolases from Hafnia paralvei and Yersinia aldovae. 3D X-ray structures of complexes with substrate SFP and product DHAP reveal a dimer-of-dimers (tetrameric) assembly, the sulfonate binding pocket, two metal binding sites, and flexible loops that are implicated in catalysis. Both enzymes were metal dependent and exhibited high K(M) values for SFP, consistent with their role in a unidirectional nutrient acquisition pathway. Bioinformatic analysis identified a range of sulfo-EMP gene clusters containing class I/II SFP aldolases. The class I and II SFP aldolases occur exclusively within Actinobacteria and Firmicutes phyla, respectively, while both classes of enzyme occur within Proteobacteria. This work emphasizes the importance of SQ as a nutrient for diverse bacterial phyla and the different chemical strategies they use to harvest carbon from this sulfosugar.

Defining the molecular architecture, metal dependence, and distribution of metal-dependent class II sulfofructose-1-phosphate aldolases.,Sharma M, Kaur A, Soler NM, Lingford JP, Epa R, Goddard-Borger ED, Davies GJ, Williams SJ J Biol Chem. 2023 Oct 12:105338. doi: 10.1016/j.jbc.2023.105338. PMID:37838169^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.