Literature summary for 3.1.26.4 extracted from

Jongruja, N.; You, D.J.; Kanaya, E.; Koga, Y.; Takano, K.; Kanaya, S.
The N-terminal hybrid binding domain of RNase HI from Thermotoga maritima is important for substrate binding and Mg2+-dependent activity (2010), FEBS J., 277, 4474-4489.

Search for more literature for 3.1.26.4

Cloned(Commentary)

Cloned (Comment)	Organism
RNase HI sequence comparisons, expression of wild-type and mutant enzymes in Escherichia coli	Thermotoga maritima

Protein Variants

Protein Variants	Comment	Organism
additional information	the C-terminal RNase H domain loses the ability to suppress the RNase H deficiency of an Escherichia coli rnhA mutant. The substrate binding affinity of Tma-RNase HI is greatly reduced on removal of the hybrid binding domain or the mutation	Thermotoga maritima
W22A	site-directed mutagenesis, located in the hybrid binding domain	Thermotoga maritima

KM Value [mM]

KM Value [mM]	KM Value Maximum [mM]	Substrate	Comment	Organism	Structure
0.00039	-	M13 DNA/RNA hybrid	wild-type enzyme, pH 9.0, 30°C, in presence of 50 mM KCl	Thermotoga maritima

Metals/Ions

Metals/Ions	Comment	Organism	Structure
KCl	activates, best at 50 mM for the full-length enzyme, and at 10 mM for the C-terminal domain	Thermotoga maritima
Mg2+	dependent on	Thermotoga maritima
Mn2+	activates, less active than Mg2+	Thermotoga maritima
additional information	Tma-RNase HI prefers Mg2+ to Mn2+ for activity, and specifically loses most of the Mg2+-dependent activity on removal of the hybrid binding domain and 87% of it by the mutation at the hybrid binding domain. Activity profiles of different metals and salt concentrations	Thermotoga maritima

Natural Substrates/ Products (Substrates)

Natural Substrates	Organism	Comment (Nat. Sub.)	Natural Products	Comment (Nat. Pro.)	Rev.	Reac.
additional information	Thermotoga maritima	ribonuclease H is an enzyme that specifically cleaves RNA of RNA?DNA hybrids	?	-	?

Organism

Organism	UniProt	Comment	Textmining
Thermotoga maritima	Q9X122	-	-

Specific Activity [micromol/min/mg]

Specific Activity Minimum [µmol/min/mg]	Specific Activity Maximum [µmol/min/mg]	Comment	Organism
0.48	-	substrate M13 DNA/RNA hybrid, enzyme mutant W22A, pH 9.0, 30°C, in presence of 50 mM KCl	Thermotoga maritima
3.6	-	substrate M13 DNA/RNA hybrid, wild-type enzyme, pH 9.0, 30°C, in presence of 50 mM KCl	Thermotoga maritima

Substrates and Products (Substrate)

Substrates	Comment Substrates	Organism	Products	Comment (Products)	Rev.	Reac.
D13-R4-D12-D29 hybrid + H2O	-	Thermotoga maritima	?	-	?
M13 DNA/RNA hybrid + H2O	-	Thermotoga maritima	?	-	?
additional information	ribonuclease H is an enzyme that specifically cleaves RNA of RNA?DNA hybrids	Thermotoga maritima	?	-	?
additional information	determination of cleavage-site specificity, overview	Thermotoga maritima	?	-	?

Subunits

Subunits	Comment	Organism
More	Tma-RNase HI contains a hybrid binding domain at the N-terminal region. Analysis for interaction between the C-terminal and the hybrid binding domains, overview	Thermotoga maritima

Synonyms

Synonyms	Comment	Organism
RNase H	-	Thermotoga maritima
RNase HI	-	Thermotoga maritima

Temperature Optimum [°C]

Temperature Optimum [°C]	Temperature Optimum Maximum [°C]	Comment	Organism
30	-	assay at	Thermotoga maritima

pH Optimum

pH Optimum Minimum	pH Optimum Maximum	Comment	Organism
9	-	assay at	Thermotoga maritima

General Information

General Information	Comment	Organism
additional information	the C-terminal RNase H domain loses the ability to suppress the RNase H deficiency of an Escherichia coli rnhA mutant, the hybrid binding domain is responsible for in vivo RNase H activity	Thermotoga maritima

Use of this online version of BRENDA is free under the CC BY 4.0 license. See terms of use for full details.

Release 2023.1 (January 2023)