Browse
Submit Data
Databases
API
Help

Dataset Information

0 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

The human DINB1 gene encodes the DNA polymerase Poltheta.

ABSTRACT: The human DINB1 gene shares a high degree of homology with the Escherichia coli dinB gene. Here, we purify the hDINB1-encoded protein and show that it is a DNA polymerase. Because hDinB1 is the eighth eukaryotic DNA polymerase to be described, we have named it DNA polymerase (Pol) theta. hPoltheta is unable to bypass a cis-syn thymine-thymine dimer, nor does it bypass a (6-4) photoproduct or an abasic site. We also examine the fidelity of hPoltheta on nondamaged DNA templates by steady-state kinetic analyses and find that hPoltheta misincorporates deoxynucleotides with a frequency of about 10(-3) to 10(-4). We discuss the relationship between the fidelity of hPoltheta and its inability to bypass DNA damage.

SUBMITTER: Johnson RE

PROVIDER: S-EPMC18103 | biostudies-literature | 2000 Apr

REPOSITORIES: biostudies-literature

ACCESS DATA

Json Xml

Publications

The human DINB1 gene encodes the DNA polymerase Poltheta.

Johnson R E RE Prakash S S Prakash L L

Proceedings of the National Academy of Sciences of the United States of America 20000401 8

The human DINB1 gene shares a high degree of homology with the Escherichia coli dinB gene. Here, we purify the hDINB1-encoded protein and show that it is a DNA polymerase. Because hDinB1 is the eighth eukaryotic DNA polymerase to be described, we have named it DNA polymerase (Pol) theta. hPoltheta is unable to bypass a cis-syn thymine-thymine dimer, nor does it bypass a (6-4) photoproduct or an abasic site. We also examine the fidelity of hPoltheta on nondamaged DNA templates by steady-state kin ...[more]

PMID: 10760255

Similar Datasets

A human homolog of the Saccharomyces cerevisiae REV3 gene, which encodes the catalytic subunit of DNA polymerase zeta.

Project description:To get a better understanding of mutagenic mechanisms in humans, we have cloned and sequenced the human homolog of the Saccharomyces cerevisiae REV3 gene. The yeast gene encodes the catalytic subunit of DNA polymerase zeta, a nonessential enzyme that is thought to carry out translesion replication and is responsible for virtually all DNA damage-induced mutagenesis and the majority of spontaneous mutagenesis. The human gene encodes an expected protein of 3,130 residues, about twice the size of the yeast protein (1,504 aa). The two proteins are 29% identical in an amino-terminal region of approximately 340 residues, 39% identical in a carboxyl-terminal region of approximately 850 residues, and 29% identical in a 55-residue region in the middle of the two genes. The sequence of the expected protein strongly predicts that it is the catalytic subunit of a DNA polymerase of the pol zeta type; the carboxyl-terminal domain possesses, in the right order, the six motifs characteristic of eukaryotic DNA polymerases, most closely resembles yeast pol zeta among all polymerases in the GenBank database, and is different from the human alpha, delta, and epsilon enzymes. Human cells expressing high levels of an hsREV3 antisense RNA fragment grow normally, but show little or no UV-induced mutagenesis and are slightly more sensitive to killing by UV. The human gene therefore appears to carry out a function similar to that of its yeast counterpart.

| S-EPMC22668 | biostudies-literature

The human THAP9 gene encodes an active P-element DNA transposase.

Project description:The human genome contains ~50 genes that were derived from transposable elements or transposons, and many are now integral components of cellular gene expression programs. The human THAP9 gene is related to the Drosophila P-element transposase. Here, we show that human THAP9 can mobilize Drosophila P-elements in both Drosophila and human cells. Chimeric proteins formed between the Drosophila P-element transposase N-terminal THAP DNA binding domain and the C-terminal regions of human THAP9 can also mobilize Drosophila P elements. Our results indicate that human THAP9 is an active DNA transposase that, although "domesticated," still retains the catalytic activity to mobilize P transposable elements across species.

| S-EPMC3779457 | biostudies-literature

The human DNA ligase III gene encodes nuclear and mitochondrial proteins.

Project description:We provide evidence that the human DNA ligase III gene encodes a mitochondrial form of this enzyme. First, the DNA ligase III cDNA contains an in-frame ATG located upstream from the putative translation initiation start site. The DNA sequence between these two ATG sites encodes an amphipathic helix similar to previously identified mitochondrial targeting peptides. Second, recombinant green fluorescent protein harboring this sequence at its amino terminus was efficiently targeted to the mitochondria of Cos-1 monkey kidney cells. In contrast, native green fluorescent protein distributed to the cytosol. Third, a series of hemagglutinin-DNA ligase III minigene constructs were introduced into Cos-1 cells, and immunocytochemistry was used to determine subcellular localization of the epitope-tagged DNA ligase III protein. These experiments revealed that inactivation of the upstream ATG resulted in nuclear accumulation of the DNA ligase III protein, whereas inactivation of the downstream ATG abolished nuclear localization and led to accumulation within the mitochondrial compartment. Fourth, mitochondrial protein extracts prepared from human cells overexpressing antisense DNA ligase III mRNA possessed substantially less DNA ligase activity than did mitochondrial extracts prepared from control cells. DNA end-joining activity was also substantially reduced in extracts prepared from antisense mRNA-expressing cells. From these results, we conclude that the human DNA ligase III gene encodes both nuclear and mitochondrial enzymes. DNA ligase plays a central role in DNA replication, recombination, and DNA repair. Thus, identification of a mitochondrial form of this enzyme provides a tool with which to dissect mammalian mitochondrial genome dynamics.

| S-EPMC84244 | biostudies-literature

White spot syndrome virus Orf514 encodes a bona fide DNA polymerase.

Project description:White spot syndrome virus (WSSV) is the causative agent of white spot syndrome, one of the most devastating diseases in shrimp aquaculture. The genome of WSSV includes a gene that encodes a putative family B DNA polymerase (ORF514), which is 16% identical in amino acid sequence to the Herpes virus 1 DNA polymerase. The aim of this work was to demonstrate the activity of the WSSV ORF514-encoded protein as a DNA polymerase and hence a putative antiviral target. A 3.5 kbp fragment encoding the conserved polymerase and exonuclease domains of ORF514 was overexpressed in bacteria. The recombinant protein showed polymerase activity but with very low level of processivity. Molecular modeling of the catalytic protein core encoded in ORF514 revealed a canonical polymerase fold. Amino acid sequence alignments of ORF514 indicate the presence of a putative PIP box, suggesting that the encoded putative DNA polymerase may use a host processivity factor for optimal activity. We postulate that WSSV ORF514 encodes a bona fide DNA polymerase that requires accessory proteins for activity and maybe target for drugs or compounds that inhibit viral DNA replication.

| S-EPMC6259105 | biostudies-literature

Promiscuous DNA synthesis by human DNA polymerase ?.

Project description:The biological role of human DNA polymerase ? (POLQ) is not yet clearly defined, but it has been proposed to participate in several cellular processes based on its translesion synthesis capabilities. POLQ is a low-fidelity polymerase capable of efficient bypass of blocking lesions such as abasic sites and thymine glycols as well as extension of mismatched primer termini. Here, we show that POLQ possesses a DNA polymerase activity that appears to be template independent and allows efficient extension of single-stranded DNA as well as duplex DNA with either protruding or multiply mismatched 3'-OH termini. We hypothesize that this DNA synthesis activity is related to the proposed role for POLQ in the repair or tolerance of double-strand breaks.

| S-EPMC3315306 | biostudies-literature

Mimivirus encodes a multifunctional primase with DNA/RNA polymerase, terminal transferase and translesion synthesis activities.

Project description:Acanthamoeba polyphaga mimivirus is an amoeba-infecting giant virus with over 1000 genes including several involved in DNA replication and repair. Here, we report the biochemical characterization of gene product 577 (gp577), a hypothetical protein (product of L537 gene) encoded by mimivirus. Sequence analysis and phylogeny suggested gp577 to be a primase-polymerase (PrimPol)-the first PrimPol to be identified in a nucleocytoplasmic large DNA virus (NCLDV). Recombinant gp577 protein purified as a homodimer and exhibited de novo RNA as well as DNA synthesis on circular and linear single-stranded DNA templates. Further, gp577 extends a DNA/RNA primer annealed to a DNA or RNA template using deoxyribonucleoties (dNTPs) or ribonucleotides (NTPs) demonstrating its DNA/RNA polymerase and reverse transcriptase activity. We also show that gp577 possesses terminal transferase activity and is capable of extending ssDNA and dsDNA with NTPs and dNTPs. Mutation of the conserved primase motif residues of gp577 resulted in the loss of primase, polymerase, reverse transcriptase and terminal transferase activities. Additionally, we show that gp577 possesses translesion synthesis (TLS) activity. Mimiviral gp577 represents the first protein from an NCLDV endowed with primase, polymerase, reverse transcriptase, terminal transferase and TLS activities.

| S-EPMC6648351 | biostudies-literature

Characterization of the DNA polymerase gene of human herpesvirus 6.

Project description:The construction of a recombinant bacteriophage lambda library containing overlapping clones covering 155 kbp of the 161-kbp genome of the Ugandan U1102 isolate of human herpesvirus 6 (HHV-6) is described. The use of degenerate-primer polymerase chain reaction allowed the isolation of a DNA probe for the DNA polymerase gene of HHV-6, which was subsequently used to isolate and position the pol gene on the physical map of the viral genome. A 4.4-kbp EcoRI DNA restriction fragment containing the pol gene was isolated and sequenced. The open reading frames flanking the pol gene code for the HHV-6 glycoprotein B gene and the human cytomegalovirus UL53 homolog. This arrangement is different from that seen in the alpha and gamma herpesvirus families, lending further support to the notion that HHV-6 is a member of the beta herpesvirus group.

| S-EPMC248922 | biostudies-other

PDIP46 (DNA polymerase ? interacting protein 46) is an activating factor for human DNA polymerase ?.

Project description:PDIP46 (SKAR, POLDIP3) was discovered through its interaction with the p50 subunit of human DNA polymerase ? (Pol ?). Its functions in DNA replication are unknown. PDIP46 associates with Pol ? in cell extracts both by immunochemical and protein separation methods, as well as by ChIP analyses. PDIP46 also interacts with PCNA via multiple copies of a novel PCNA binding motif, the APIMs (AlkB homologue-2 PCNA-Interacting Motif). Sites for both p50 and PCNA binding were mapped to the N-terminal region containing the APIMs. Functional assays for the effects of PDIP46 on Pol ? activity on singly primed ssM13 DNA templates revealed that it is a novel and potent activator of Pol ?. The effects of PDIP46 on Pol ? in primer extension, strand displacement and synthesis through simple hairpin structures reveal a mechanism where PDIP46 facilitates Pol ?4 synthesis through regions of secondary structure on complex templates. In addition, evidence was obtained that PDIP46 is also capable of exerting its effects by a direct interaction with Pol ?, independent of PCNA. Mutation of the Pol ? and PCNA binding region resulted in a loss of PDIP46 functions. These studies support the view that PDIP46 is a novel accessory protein for Pol ? that is involved in cellular DNA replication. This raises the possibility that altered expression of PDIP46 or its mutation may affect Pol ? functions in vivo, and thereby be a nexus for altered genomic stability.

| S-EPMC4868757 | biostudies-literature

The human hGSTA5 gene encodes an enzymatically active protein.

Project description:Of the five human Alpha-class glutathione transferases, expression of hGSTA5 has not been experimentally documented, even though in silico the hGSTA5 sequence can be assembled into a mRNA and translated. The present work was undertaken to determine whether hGSTA5 is functional.Human K562 cells were transfected with the hGSTA5 gene driven by the CMV promoter, and hGSTA5 cDNA was recovered from mature mRNA by reverse transcription. The cDNA was used in bacterial and eukaryotic protein expression systems. The resulting protein, after purification by glutathione affinity chromatography where appropriate, was tested for glutathione transferase activity.Human K562 cells transfected with the hGSTA5 gene under control of a CMV promoter produced a fully spliced mRNA which, after reverse transcription and expression in E. coli, yielded a protein that catalyzed the conjugation of the lipid peroxidation product 4-hydroxynonenal to glutathione. Similarly, transfection of human HEK-293 cells with the hGSTA5 gene driven by the CMV promoter led to an elevated 4-hydroxynonenal-conjugating activity in the cell lysate. In addition, translation of hGSTA5 cDNA in a cell-free eukaryotic system gave rise to a protein with 4-hydroxynonenal-conjugating activity.hGSTA5 can be processed to a mature mRNA which is translation-competent, producing a catalytically active enzyme.Because a functional gene would not be maintained in the absence of selective pressure, we conclude that the native hGSTA5 promoter is active but has a spatially or temporally restricted expression pattern, and/or is expressed only under specific (patho)physiological conditions.

| S-EPMC2788006 | biostudies-literature

Human herpesvirus 8 gene encodes a functional thymidylate synthase.

Project description:We demonstrate that human herpesvirus 8, obtained from the lymphoma cell line BC-3 as well as from Kaposi's sarcoma lesions, carries a gene that encodes a functional thymidylate synthase (TS). The particular characteristics of this enzyme are studied and compared to the characteristics of TSs encoded by other organisms.

| S-EPMC136588 | biostudies-literature

OmicsDI is part of the ELIXIR infrastructure

OmicsDI is an Elixir interoperability service. Learn more ›

Tweets

OmicsDI Databases

PRIDE
PeptideAtlas
MassIVE
JPOST Repository
Physiome Model Repository

EGA
EVA
ENA
LINCS
PAXDB
Cell Collective

MetaboLights
Metabolomics Workbench
MetabolomeExpress
GNPS
BioModels
FAIRDOMHub

ArrayExpress
dbGaP
ExpressionAtlas
GEO
NODE

Information

Databases
Help
API
Contact us
Code on GitHub
Terms of use
Submit Data