DnaQ-like (or DEDD) 3'-5' exonuclease domain superfamily; The DnaQ-like exonuclease superfamily is a structurally conserved group of 3'-5' exonucleases, which catalyze the excision of nucleoside monophosphates at the DNA or RNA termini in the 3'-5' direction. It is also called the DEDD superfamily, after the four invariant acidic residues present in the catalytic site of its members. The superfamily consists of DNA- and RNA-processing enzymes such as the proofreading domains of DNA polymerases, other DNA exonucleases, RNase D, RNase T, Oligoribonuclease and RNA exonucleases (REX). The DnaQ-like exonuclease domain contains three conserved sequence motifs termed ExoI, ExoII and ExoIII, which are clustered around the active site and contain four conserved acidic residues that serve as ligands for the two metal ions required for catalysis. The conservation patterns of the three motifs may vary among different subfamilies. DnaQ-like exonucleases are classified as DEDDy or DEDDh exonucleases depending on the variation of motif III as YX(3)D or HX(4)D, respectively. The significance of the motif differences is still unclear. Almost all RNase families in this superfamily are present only in eukaryotes and bacteria, but not in archaea, suggesting a later origin, which in some cases are accompanied by horizontal gene transfer.
The actual alignment was detected with superfamily member TIGR01298:
Pssm-ID: 447876 [Multi-domain] Cd Length: 200 Bit Score: 359.15 E-value: 4.60e-128
ribonuclease T; This model describes ribonuclease T, an enzyme found so far only in ...
10-209
4.60e-128
ribonuclease T; This model describes ribonuclease T, an enzyme found so far only in gamma-subdivision Proteobacteria such as Escherichia coli and Xylella fastidiosa. Ribonuclease T is homologous to the DNA polymerase III alpha chain. It can liberate AMP from the common C-C-A terminus of uncharged tRNA. It appears also to be involved in RNA maturation. It also acts as a 3' to 5' single-strand DNA-specific exonuclease; it is distinctive for its ability to remove residues near a double-stranded stem. Ribonuclease T is a high copy suppressor in E. coli of a uv-repair defect caused by deletion of three other single-stranded DNA exonucleases. [Transcription, RNA processing]
Pssm-ID: 188129 [Multi-domain] Cd Length: 200 Bit Score: 359.15 E-value: 4.60e-128
DEDDh 3'-5' exonuclease domain of RNase T; RNase T is a DEDDh-type DnaQ-like 3'-5' ...
13-201
9.85e-126
DEDDh 3'-5' exonuclease domain of RNase T; RNase T is a DEDDh-type DnaQ-like 3'-5' exoribonuclease E implicated in the 3' maturation of small stable RNAs and 23srRNA, and in the end turnover of tRNA. It contains three conserved sequence motifs termed ExoI, ExoII and ExoIII, with a specific Hx(4)D conserved pattern at ExoIII. These motifs are clustered around the active site and contain four conserved acidic residues that serve as ligands for the two metal ions required for catalysis. RNase T is related to the proofreading domain of DNA polymerase III. Despite its important role, RNase T is mainly found only in gammaproteobacteria. It is speculated that it might have originated from DNA polymerase III at the time the gamma division of proteobacteria diverged from other bacteria. RNase T is a homodimer with the catalytic residues of one monomer contacting a large basic patch on the other monomer to form a functional active site.
Pssm-ID: 99837 [Multi-domain] Cd Length: 189 Bit Score: 352.75 E-value: 9.85e-126
ribonuclease T; This model describes ribonuclease T, an enzyme found so far only in ...
10-209
4.60e-128
ribonuclease T; This model describes ribonuclease T, an enzyme found so far only in gamma-subdivision Proteobacteria such as Escherichia coli and Xylella fastidiosa. Ribonuclease T is homologous to the DNA polymerase III alpha chain. It can liberate AMP from the common C-C-A terminus of uncharged tRNA. It appears also to be involved in RNA maturation. It also acts as a 3' to 5' single-strand DNA-specific exonuclease; it is distinctive for its ability to remove residues near a double-stranded stem. Ribonuclease T is a high copy suppressor in E. coli of a uv-repair defect caused by deletion of three other single-stranded DNA exonucleases. [Transcription, RNA processing]
Pssm-ID: 188129 [Multi-domain] Cd Length: 200 Bit Score: 359.15 E-value: 4.60e-128
DEDDh 3'-5' exonuclease domain of RNase T; RNase T is a DEDDh-type DnaQ-like 3'-5' ...
13-201
9.85e-126
DEDDh 3'-5' exonuclease domain of RNase T; RNase T is a DEDDh-type DnaQ-like 3'-5' exoribonuclease E implicated in the 3' maturation of small stable RNAs and 23srRNA, and in the end turnover of tRNA. It contains three conserved sequence motifs termed ExoI, ExoII and ExoIII, with a specific Hx(4)D conserved pattern at ExoIII. These motifs are clustered around the active site and contain four conserved acidic residues that serve as ligands for the two metal ions required for catalysis. RNase T is related to the proofreading domain of DNA polymerase III. Despite its important role, RNase T is mainly found only in gammaproteobacteria. It is speculated that it might have originated from DNA polymerase III at the time the gamma division of proteobacteria diverged from other bacteria. RNase T is a homodimer with the catalytic residues of one monomer contacting a large basic patch on the other monomer to form a functional active site.
Pssm-ID: 99837 [Multi-domain] Cd Length: 189 Bit Score: 352.75 E-value: 9.85e-126
DEDDh 3'-5' exonuclease domain family; DEDDh exonucleases, part of the DnaQ-like (or DEDD) ...
20-194
1.11e-22
DEDDh 3'-5' exonuclease domain family; DEDDh exonucleases, part of the DnaQ-like (or DEDD) exonuclease superfamily, catalyze the excision of nucleoside monophosphates at the DNA or RNA termini in the 3'-5' direction. These proteins contain four invariant acidic residues in three conserved sequence motifs termed ExoI, ExoII and ExoIII. DEDDh exonucleases are classified as such because of the presence of specific Hx(4)D conserved pattern at the ExoIII motif. The four conserved acidic residues are clustered around the active site and serve as ligands for the two metal ions required for catalysis. Most DEDDh exonucleases are the proofreading subunits (epsilon) or domains of bacterial DNA polymerase III, the main replicating enzyme in bacteria, which functions as the chromosomal replicase. Other members include other DNA and RNA exonucleases such as RNase T, Oligoribonuclease, and RNA exonuclease (REX), among others.
Pssm-ID: 176648 [Multi-domain] Cd Length: 159 Bit Score: 89.67 E-value: 1.11e-22
DEDDh 3'-5' exonuclease domain of the epsilon subunit of Escherichia coli DNA polymerase III ...
20-155
4.62e-06
DEDDh 3'-5' exonuclease domain of the epsilon subunit of Escherichia coli DNA polymerase III and similar proteins; This subfamily is composed of the epsilon subunit of Escherichia coli DNA polymerase III (Pol III) and similar proteins. Pol III is the main DNA replicating enzyme in bacteria, functioning as the chromosomal replicase. It is a holoenzyme complex of ten different subunits, three of which (alpha, epsilon, and theta) compose the catalytic core. The Pol III epsilon subunit, encoded by the dnaQ gene, is a DEDDh-type 3'-5' exonuclease which is responsible for the proofreading activity of the polymerase, increasing the fidelity of DNA synthesis. It contains three conserved sequence motifs termed ExoI, ExoII and ExoIII, with a specific Hx(4)D conserved pattern at ExoIII. These motifs are clustered around the active site and contain four conserved acidic residues that serve as ligands for the two metal ions required for catalysis. The epsilon subunit of Pol III also functions as a stabilizer of the holoenzyme complex.
Pssm-ID: 99835 [Multi-domain] Cd Length: 167 Bit Score: 45.22 E-value: 4.62e-06
an uncharacterized bacterial subgroup of the DEDDh 3'-5' exonuclease domain family with ...
20-196
2.54e-04
an uncharacterized bacterial subgroup of the DEDDh 3'-5' exonuclease domain family with similarity to the epsilon subunit of DNA polymerase III; This subfamily is composed of uncharacterized bacterial proteins with similarity to the epsilon subunit of DNA polymerase III (Pol III), a multisubunit polymerase which is the main DNA replicating enzyme in bacteria, functioning as the chromosomal replicase. The Pol III holoenzyme is a complex of ten different subunits, three of which (alpha, epsilon, and theta) compose the catalytic core. The Pol III epsilon subunit, encoded by the dnaQ gene, is a DEDDh-type 3'-5' exonuclease which is responsible for the proofreading activity of the polymerase, increasing the fidelity of DNA synthesis. It contains three conserved sequence motifs termed ExoI, ExoII and ExoIII, with a specific Hx(4)D conserved pattern at ExoIII. These motifs are clustered around the active site and contain four conserved acidic residues that serve as ligands for the two metal ions required for catalysis. The epsilon subunit of Pol III also functions as a stabilizer of the holoenzyme complex.
Pssm-ID: 99834 [Multi-domain] Cd Length: 156 Bit Score: 39.80 E-value: 2.54e-04
N-terminal DEDDh 3'-5' exonuclease domain of Escherichia coli exonuclease I and similar ...
17-146
2.92e-04
N-terminal DEDDh 3'-5' exonuclease domain of Escherichia coli exonuclease I and similar proteins; This subfamily is composed of the N-terminal domain of Escherichia coli exonuclease I (ExoI) and similar proteins. ExoI is a monomeric enzyme that hydrolyzes single stranded DNA in the 3' to 5' direction. It plays a role in DNA recombination and repair. It primarily functions in repairing frameshift mutations. The N-terminal domain of ExoI is a DEDDh-type DnaQ-like 3'-5 exonuclease containing three conserved sequence motifs termed ExoI, ExoII and ExoIII, with a specific Hx(4)D conserved pattern at ExoIII. These motifs are clustered around the active site and contain four conserved acidic residues that serve as ligands for the two metal ions required for catalysis. The ExoI structure is unique among DnaQ family enzymes in that there is a large distance between the two metal ions required for catalysis and the catalytic histidine is oriented away from the active site.
Pssm-ID: 99841 [Multi-domain] Cd Length: 183 Bit Score: 40.32 E-value: 2.92e-04
exonuclease, DNA polymerase III, epsilon subunit family; All proteins in this family for which ...
20-197
6.26e-04
exonuclease, DNA polymerase III, epsilon subunit family; All proteins in this family for which functions are known are components of the DNA polymerase III complex (epsilon subunit). There is, however, an outgroup that includes paralogs in some gamma-proteobacteria and the n-terminal region of DinG from some low GC gram positive bacteria. This family is based on the phylogenomic analysis of JA Eisen (1999, Ph.D. Thesis, Stanford University). [DNA metabolism, Degradation of DNA]
Pssm-ID: 129663 [Multi-domain] Cd Length: 217 Bit Score: 39.36 E-value: 6.26e-04
DnaQ-like (or DEDD) 3'-5' exonuclease domain superfamily; The DnaQ-like exonuclease superfamily is a structurally conserved group of 3'-5' exonucleases, which catalyze the excision of nucleoside monophosphates at the DNA or RNA termini in the 3'-5' direction. It is also called the DEDD superfamily, after the four invariant acidic residues present in the catalytic site of its members. The superfamily consists of DNA- and RNA-processing enzymes such as the proofreading domains of DNA polymerases, other DNA exonucleases, RNase D, RNase T, Oligoribonuclease and RNA exonucleases (REX). The DnaQ-like exonuclease domain contains three conserved sequence motifs termed ExoI, ExoII and ExoIII, which are clustered around the active site and contain four conserved acidic residues that serve as ligands for the two metal ions required for catalysis. The conservation patterns of the three motifs may vary among different subfamilies. DnaQ-like exonucleases are classified as DEDDy or DEDDh exonucleases depending on the variation of motif III as YX(3)D or HX(4)D, respectively. The significance of the motif differences is still unclear. Almost all RNase families in this superfamily are present only in eukaryotes and bacteria, but not in archaea, suggesting a later origin, which in some cases are accompanied by horizontal gene transfer.
Pssm-ID: 176647 [Multi-domain] Cd Length: 96 Bit Score: 36.26 E-value: 1.98e-03
Database: CDSEARCH/cdd Low complexity filter: no Composition Based Adjustment: yes E-value threshold: 0.01
References:
Wang J et al. (2023), "The conserved domain database in 2023", Nucleic Acids Res.51(D)384-8.
Lu S et al. (2020), "The conserved domain database in 2020", Nucleic Acids Res.48(D)265-8.
Marchler-Bauer A et al. (2017), "CDD/SPARCLE: functional classification of proteins via subfamily domain architectures.", Nucleic Acids Res.45(D)200-3.
of the residues that compose this conserved feature have been mapped to the query sequence.
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