7AG4

Crystal structure of active site mutant of SQ Isomerase (YihS-H248A) from Salmonella enterica in complex with sulfofructose (SF)

7AG4 の概要

• エントリーDOI: 10.2210/pdb7ag4/pdb
• 分子名称: Sulfoquinovose isomerase, 6-deoxy-6-sulfo-D-fructose (3 entities in total)
• 機能のキーワード: sulfofructose, sulfoquinovose, sq isomerase, sulfoglycolysis, isomerase
• 由来する生物種: Salmonella typhimurium (strain LT2 / SGSC1412 / ATCC 700720)
• タンパク質・核酸の鎖数: 6
• 化学式量合計: 299603.72

構造登録者

Sharma, M.,Davies, G.J. (登録日: 2020-09-21, 公開日: 2021-04-14, 最終更新日: 2024-01-31)

主引用文献

Sharma, M.,Abayakoon, P.,Epa, R.,Jin, Y.,Lingford, J.P.,Shimada, T.,Nakano, M.,Mui, J.W.,Ishihama, A.,Goddard-Borger, E.D.,Davies, G.J.,Williams, S.J.
Molecular Basis of Sulfosugar Selectivity in Sulfoglycolysis.
Acs Cent.Sci., 7:476-487, 2021

PubMed Abstract: 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. Our data show that despite the superficial similarity of this pathway to glycolysis, the sulfoglycolytic enzymes are specific for SQ metabolites and are not catalytically active on related metabolites from glycolytic pathways. This observation is rationalized by three-dimensional structures of each enzyme, which reveal the presence of conserved sulfonate binding pockets. We show that SQ isomerase acts preferentially on the β-anomer of SQ and reversibly produces both SF and sulforhamnose (SR), a previously unknown sugar that acts as a derepressor for the transcriptional repressor CsqR that regulates SQ-utilization. We also demonstrate that SF kinase is a key regulatory enzyme for the pathway that experiences complex modulation by the metabolites SQ, SLA, AMP, ADP, ATP, F6P, FBP, PEP, DHAP, and citrate, and we show that SFP aldolase reversibly synthesizes SFP. This body of work provides fresh insights into the mechanism, specificity, and regulation of sulfoglycolysis and has important implications for understanding how this biochemistry interfaces with central metabolism in prokaryotes to process this major repository of biogeochemical sulfur.

PubMed: 33791429
DOI: 10.1021/acscentsci.0c01285

実験手法

X-RAY DIFFRACTION (2.13 Å)