Cloned (Comment) | Organism |
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expression of wild-type and truncated D107N mutant enzymes in Escherichia coli | Thermotoga maritima |
Crystallization (Comment) | Organism |
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RNase H2 in complex with nucleic acid containing a 5'RNA-DNA3' junction, X-ray diffraction structure determination and analysis at 2.0 A resolution | Thermotoga maritima |
Protein Variants | Comment | Organism |
---|---|---|
D107N | site-directed mutagenesis, inactive mutant | Thermotoga maritima |
G21S | site-directed mutagenesis, the mutation is located in the conserved GRG 2'-OH-sensing motif, the mutant has much lower activity on RNA/DNA and DNA-RNA/DNA in the presence of Mn2+. In the presence of Mg2+ it also shows reduced activity on substrates with (5')RNA-DNA(3') junction | Thermotoga maritima |
additional information | construction of a truncated mutant with 15 residues removed from the C-terminus | Thermotoga maritima |
R22A | site-directed mutagenesis, the R22A mutation does not alter Tm-RNase H2 activity on most substrates compared to the wild-type enzyme | Thermotoga maritima |
Y163F | site-directed mutagenesis, Y163 is a key residue involved in 2'-OH binding, and its mutation to phenylalanine seriously reduces activity against all tested substrates | Thermotoga maritima |
Metals/Ions | Comment | Organism | Structure |
---|---|---|---|
Mg2+ | the full-length and C-terminally truncated enzymes have similar activity, and both are around 600fold more active in the presence of Mn2+ compared to Mg2+, binding structure and activation mechanism, overview | Thermotoga maritima | |
Mn2+ | the full-length and C-terminally truncated enzymes have similar activity, and both are around 600fold more active in the presence of Mn2+ compared to Mg2+, binding structure and activation mechanism, overview | Thermotoga maritima |
Natural Substrates | Organism | Comment (Nat. Sub.) | Natural Products | Comment (Nat. Pro.) | Rev. | Reac. |
---|---|---|---|---|---|---|
additional information | Thermotoga maritima | RNase H2 hydrolyzes RNA of RNA/DNA hybrids and can nick duplex DNAs containing a single ribonucleotide. It shows a unique mechanism of recognition and substrate-assisted cleavage with preference for junction substrates. A conserved tyrosine residue distorts the nucleic acid at the junction, allowing the substrate to function in catalysis by participating in coordination of the active site metal ion | ? | - |
? |
Organism | UniProt | Comment | Textmining |
---|---|---|---|
Thermotoga maritima | Q9X017 | - |
- |
Substrates | Comment Substrates | Organism | Products | Comment (Products) | Rev. | Reac. |
---|---|---|---|---|---|---|
DNA-RNA-DNA/DNA hybrid + H2O | a duplex containing a (5')RNA-DNA(3') junction with one, three, or six ribonucleotides, i.e. DNA5-RNA1-DNA6/DNA12, DNA3-RNA3-DNA6/DNA12, and RNA6-DNA6/DNA12, and a substrate with a (5')DNA-RNA(3') junction, DNA5-RNA7/DNA12 | Thermotoga maritima | ? | - |
? | |
additional information | RNase H2 hydrolyzes RNA of RNA/DNA hybrids and can nick duplex DNAs containing a single ribonucleotide. It shows a unique mechanism of recognition and substrate-assisted cleavage with preference for junction substrates. A conserved tyrosine residue distorts the nucleic acid at the junction, allowing the substrate to function in catalysis by participating in coordination of the active site metal ion | Thermotoga maritima | ? | - |
? | |
poly(rA)/poly(dT) + H2O | - |
Thermotoga maritima | ? | - |
? | |
RNA/DNA hybrid + H2O | an RNA/DNA hybrid (RNA12/DNA12) | Thermotoga maritima | ? | - |
? |
Synonyms | Comment | Organism |
---|---|---|
RNase H2 | - |
Thermotoga maritima |
type 2 RNase H | - |
Thermotoga maritima |
pH Optimum Minimum | pH Optimum Maximum | Comment | Organism |
---|---|---|---|
7.5 | 10 | Mg-dependent hydrolysis activity by Tm-RNase H2 gradually increases from pH 7.5 to 10 without reaching a maximum | Thermotoga maritima |
8.5 | - |
Mn-dependent activity of Tm-RNase H2 is the highest at around pH 8.5 | Thermotoga maritima |
pH Minimum | pH Maximum | Comment | Organism |
---|---|---|---|
7.5 | 10 | activity range dependent on cation added | Thermotoga maritima |
General Information | Comment | Organism |
---|---|---|
additional information | the full-length and C-terminally truncated enzymes have similar activity, and both are around 600fold more active in the presence of Mn2+ compared to Mg2+. Residue Y163 is important for binding of both (5')RNA-DNA(3') junctions and RNA/DNA substrates | Thermotoga maritima |
physiological function | RNase H2 junction recognition is important for the removal of RNA embedded in DNA and may play an important role in DNA replication and repair | Thermotoga maritima |