Any feedback?
Please rate this page
(literature.php)
(0/150)

BRENDA support

Literature summary for 1.8.5.3 extracted from

  • Mintmier, B.; McGarry, J.M.; Bain, D.J.; Basu, P.
    Kinetic consequences of the endogenous ligand to molybdenum in the DMSO reductase family a case study with periplasmic nitrate reductase (2021), J. Biol. Inorg. Chem., 26, 13-28 .
    View publication on PubMed

Protein Variants

Protein Variants Comment Organism
additional information molybdopterin enzyme periplasmic nitrate reductase (NapA, EC 1.9.6.1) is utilized as a vehicle to understand the substrate preference and delineate the kinetic underpinning of the differences imposed by exchanging the molybdenum ligands. The Mo-coordinating residue mutant C176D of NapA (EC 1.9.6.1), constructed by site-directed mutagenesis, is active with DMSO (and artificial cosubstrate methyl viologen), while the wild-type NapA is not. Kinetic consequences of the exchange of the endogenous ligand to molybdenum with other ligands within the cofactor of DMSO reductase family enzymes, overview. The C176D NapA variant shows attenuated nitrate reductase activity with a kcat 17times lower than the native NapA enzyme and a Km for nitrate that is 1.5times higher than the Km for nitrate reduction by the C176S NapA variant. Proposed interaction of the Asp ligand with bound DMSO compared to a Cys ligand at the active site in NapA variants Escherichia coli

KM Value [mM]

KM Value [mM] KM Value Maximum [mM] Substrate Comment Organism Structure
0.0282
-
Dimethylsulfoxide pH 6.0, 25┬░C, recombinant NapA mutant C176D Escherichia coli

Metals/Ions

Metals/Ions Comment Organism Structure
Molybdenum required Escherichia coli

Organism

Organism UniProt Comment Textmining
Escherichia coli
-
-
-

Substrates and Products (Substrate)

Substrates Comment Substrates Organism Products Comment (Products) Rev. Reac.
dimethylsulfoxide + methyl viologen activity of mutant C176D of periplasmic nitrate reductase NapA (EC 1.9.6.1), no activity with wild-type NapA or C176S/A NapA mutants Escherichia coli dimethylsulfide + oxidized methyl viologen + H2O
-
?

Synonyms

Synonyms Comment Organism
dimethyl sulfoxide reductase
-
Escherichia coli
DMSO reductase
-
Escherichia coli
DMSOR
-
Escherichia coli
More see also Ec 1.9.6.1 Escherichia coli

Temperature Optimum [┬░C]

Temperature Optimum [┬░C] Temperature Optimum Maximum [┬░C] Comment Organism
25
-
assay at Escherichia coli

Turnover Number [1/s]

Turnover Number Minimum [1/s] Turnover Number Maximum [1/s] Substrate Comment Organism Structure
0.023
-
Dimethylsulfoxide pH 6.0, 25┬░C, recombinant NapA mutant C176D Escherichia coli

pH Optimum

pH Optimum Minimum pH Optimum Maximum Comment Organism
6
-
recombinant NapA mutant C176D Escherichia coli

pH Range

pH Minimum pH Maximum Comment Organism
5 9 activity range, recombinant NapA mutant C176D Escherichia coli

Cofactor

Cofactor Comment Organism Structure
methyl viologen
-
Escherichia coli
molybdenum cofactor MoCo, the cofactor coordinates organic molybdopterin to molybdenum, over 50 different molybdopterin enzymes are known to catalyze a variety of chemistries in the cycling of C, N, S, As, and Se, all relying on the same basic cofactor, the MoCo. Kinetic consequences of the exchange of the endogenous ligand to molybdenum with other ligands within the cofactor of DMSO reductase family enzymes, overview. The mutant C176D of periplasmic nitrate reductase NapA (EC 1.9.6.1) is active with DMSO (and artificial cosubstrate methyl viologen), while the wild-type NapA is not Escherichia coli

General Information

General Information Comment Organism
evolution respiratory enzyme members of the DMSOR family such as nitrate reductase (NR, EC 1.9.6.1), dimethyl sulfoxide reductase (DMSOR, EC 1.8.5.3), trimethylamine N-oxide reductase (TMAOR, EC 1.7.2.3), and formate dehydrogenase (FDH) contribute to this broad diversity. The DMSOR family of enzymes has diverse active sites that vary in the first coordination sphere of the molybdenum center. Many enzymes in the DMSOR family use oxygen atom transfer (OAT) reactions for substrate transformation, e.g. periplasmic nitrate reductase (Nap) and respiratory nitrate reductase (Nar) reduce nitrate to nitrite, TMAOR reduces TMAO to TMA, and DMSOR reduces DMSO to dimethyl sulfide (DMS). Enzymes that catalyze the same reaction, such as Nap and Nar, have different molybdenum coordination spheres. In NapA, molybdenum is coordinated by a cysteine residue in the 5th position and an oxo or a sulfido group in the 6th Escherichia coli

kcat/KM [mM/s]

kcat/KM Value [1/mMs-1] kcat/KM Value Maximum [1/mMs-1] Substrate Comment Organism Structure
0.816
-
Dimethylsulfoxide pH 6.0, 25┬░C, recombinant NapA mutant C176D Escherichia coli