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

BRENDA support

Literature summary for 3.1.26.3 extracted from

  • Sun, W.; Nicholson, A.W.
    Mechanism of action of Escherichia coli ribonuclease III. Stringent chemical requirement for the glutamic acid 117 side chain and Mn2+ rescue of the Glu117Asp mutant (2001), Biochemistry, 40, 5102-5110.
    View publication on PubMed
Search for more literature for 3.1.26.3

Cloned(Commentary)

Cloned (Comment) Organism
gene rnc, overexpression of wild-type and mutants in strain BL21(DE3) as His-tagged proteins Escherichia coli

Protein Variants

Protein Variants Comment Organism
E117D site-directed mutagenesis, mutant exhibits normal homodimeric behaviour, can bind substrates but shows highly reduced hydrolysis activity compared to the wild-type enzyme Escherichia coli
E117Q site-directed mutagenesis, mutant exhibits normal homodimeric behaviour, can bind substrates but is unable to cleave the substrates Escherichia coli

Inhibitors

Inhibitors Comment Organism Structure
Mn2+ at concentrations above 5 mM, mutant E117D is not inhibited, inhibition of the wild-type enzyme by excess Mn2+ cannot be relieved by high concentrations of Mg2+, inhibition mechanism Escherichia coli
additional information no inhibition by high concentrations of Mg2+ Escherichia coli

KM Value [mM]

KM Value [mM] KM Value Maximum [mM] Substrate Comment Organism Structure
additional information
-
 additional information catalytic and substrate binding kinetics Escherichia coli
0.00011
-
 R1.1 RNA wild-type enzyme, pH 7.5, 37°C, in presence of Mn2+ Escherichia coli
0.00034
-
 R1.1 RNA wild-type enzyme, pH 7.5, 37°C, in presence of Mg2+ Escherichia coli
0.00064
-
 R1.1 RNA mutant E117D, pH 7.5, 37°C, in presence of Mn2+ Escherichia coli
38
-
 Mn2+ mutant E117D, pH 7.5, 37°C Escherichia coli

Metals/Ions

Metals/Ions Comment Organism Structure
Co2+ can partially substitute for Mg2+ or Mn2+ Escherichia coli
Mg2+ required Escherichia coli
Mn2+ can substitute for Mg2+, showing slightly higher activity with the wild-type enzyme, highly activates the mutant E117D, no activity with mutant E117Q Escherichia coli
additional information no activity of mutant E117Q with Ca2+, Ni2+, Co2+, or Sr2+ Escherichia coli
Ni2+ can partially substitute for Mg2+ or Mn2+ Escherichia coli

Molecular Weight [Da]

Molecular Weight [Da] Molecular Weight Maximum [Da] Comment Organism
29000
-
 2 * 29000, about, recombinant His-tagged enzymes, SDS-PAGE Escherichia coli

Natural Substrates/ Products (Substrates)

Natural Substrates Organism Comment (Nat. Sub.) Natural Products Comment (Nat. Pro.) Rev. Reac.
dsRNA + H2O Escherichia coli enzyme is involved in the maturation and decay of cellular, phage and plasmid RNAs mature RNA
-
 ?

Organism

Organism UniProt Comment Textmining
Escherichia coli
-
-
-

Purification (Commentary)

Purification (Comment) Organism
recombinant HIs-tagged wild-type and mutant enzymes Escherichia coli

Reaction

Reaction Comment Organism Reaction ID
Endonucleolytic cleavage to a 5'-phosphomonoester reaction mechanism, conserved Mn2+-dependent Glu117 is required, overview Escherichia coli
a

Substrates and Products (Substrate)

Substrates Comment Substrates Organism Products Comment (Products) Rev. Reac.
dsRNA + H2O
-
 Escherichia coli mature RNA
-
 ?
dsRNA + H2O enzyme is involved in the maturation and decay of cellular, phage and plasmid RNAs Escherichia coli mature RNA
-
 ?
R1.1 RNA + H2O substrate is enzymatically synthesized based on the R1.1 processing signal, which is encoded in the phage T7 genetic early regionbetween genes 1.0 and 1.1, 1 cleavage site Escherichia coli 2 fragments of R1.1 RNA
-
 ?

Subunits

Subunits Comment Organism
dimer 2 * 29000, about, recombinant His-tagged enzymes, SDS-PAGE Escherichia coli
More the enzyme consists of a catalytic and a substrate binding domain Escherichia coli

Synonyms

Synonyms Comment Organism
RNase III
-
 Escherichia coli

Temperature Optimum [°C]

Temperature Optimum [°C] Temperature Optimum Maximum [°C] Comment Organism
37
-
 assay at Escherichia coli

Turnover Number [1/s]

Turnover Number Minimum [1/s] Turnover Number Maximum [1/s] Substrate Comment Organism Structure
0.00035
-
 R1.1 RNA mutant E117D, pH 7.5, 37°C, in presence of Mn2+ Escherichia coli
0.023
-
 R1.1 RNA wild-type enzyme, pH 7.5, 37°C, in presence of Mn2+ Escherichia coli
0.063
-
 R1.1 RNA wild-type enzyme, pH 7.5, 37°C, in presence of Mg2+ Escherichia coli

pH Optimum

pH Optimum Minimum pH Optimum Maximum Comment Organism
7.5
-
 assay at Escherichia coli