scholarly journals Final Technical Report: Genetic Control of Nitrogen Assimilation in Klebsiella oxytoca.

2007 ◽  
Author(s):  
Valley Stewart
Keyword(s):  
Genetic Control ◽  
Nitrogen Assimilation ◽  
Klebsiella Oxytoca ◽  
Technical Report

Biochemical and structural investigation of sulfoacetaldehyde reductase from Klebsiella oxytoca

2019 ◽  
Vol 476 (4) ◽  
pp. 733-746 ◽  
Author(s):  
Yan Zhou ◽  
Yifeng Wei ◽  
Lianyun Lin ◽  
Tong Xu ◽  
Ee Lui Ang ◽  
...  
Keyword(s):  
Nitrogen Assimilation ◽  
Structural Investigation ◽  
Bioinformatics Analysis ◽  
Substrate Binding ◽  
Klebsiella Oxytoca ◽  
Waste Product ◽  
Sulfonate Group ◽  
Metabolic Functions ◽  
Bond Network ◽  
Β Sheet

Abstract Sulfoacetaldehyde reductase (IsfD) is a member of the short-chain dehydrogenase/reductase (SDR) family, involved in nitrogen assimilation from aminoethylsulfonate (taurine) in certain environmental and human commensal bacteria. IsfD catalyzes the reversible NADPH-dependent reduction of sulfoacetaldehyde, which is generated by transamination of taurine, forming hydroxyethylsulfonate (isethionate) as a waste product. In the present study, the crystal structure of Klebsiella oxytoca IsfD in a ternary complex with NADPH and isethionate was solved at 2.8 Å, revealing residues important for substrate binding. IsfD forms a homotetramer in both crystal and solution states, with the C-terminal tail of each subunit interacting with the C-terminal tail of the diagonally opposite subunit, forming an antiparallel β sheet that constitutes part of the substrate-binding site. The sulfonate group of isethionate is stabilized by a hydrogen bond network formed by the residues Y148, R195, Q244 and a water molecule. In addition, F249 from the diagonal subunit restrains the conformation of Y148 to further stabilize the orientation of the sulfonate group. Mutation of any of these four residues into alanine resulted in a complete loss of catalytic activity for isethionate oxidation. Biochemical investigations of the substrate scope of IsfD, and bioinformatics analysis of IsfD homologs, suggest that IsfD is related to the promiscuous 3-hydroxyacid dehydrogenases with diverse metabolic functions.

New structural insights into bacterial sulfoacetaldehyde and taurine metabolism

2020 ◽  
Vol 477 (8) ◽  
pp. 1367-1371
Author(s):  
Thore Rohwerder
Keyword(s):  
Nitrogen Assimilation ◽  
Klebsiella Oxytoca ◽  
Structural Elucidation ◽  
Degradation Pathways ◽  
Biochemical Journal ◽  
Structural Insights ◽  
Reversible Reduction

In last year's issue 4 of Biochemical Journal, Zhou et al. (Biochem J. 476, 733–746) kinetically and structurally characterized the reductase IsfD from Klebsiella oxytoca that catalyzes the reversible reduction in sulfoacetaldehyde to the corresponding alcohol isethionate. This is a key step in detoxification of the carbonyl intermediate formed in bacterial nitrogen assimilation from the α-aminoalkanesulfonic acid taurine. In 2019, the work on sulfoacetaldehyde reductase IsfD was the exciting start to a quite remarkable series of articles dealing with structural elucidation of proteins involved in taurine metabolism as well as the discovery of novel degradation pathways in bacteria.

Sign in / Sign up

Export Citation Format

Share Document