Browse
Submit Data
Databases
API
Help

Dataset Information

15 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

The crystal structure of exonuclease RecJ bound to Mn2+ ion suggests how its characteristic motifs are involved in exonuclease activity.

ABSTRACT: RecJ, a 5' to 3' exonuclease specific for single-stranded DNA, functions in DNA repair and recombination systems. We determined the crystal structure of RecJ bound to Mn(2+) ion essential for its activity. RecJ has a novel fold in which two domains are interconnected by a long helix, forming a central groove. Mn(2+) is located on the wall of the groove and is coordinated by conserved residues characteristic of a family of phosphoesterases that includes RecJ proteins. The groove is composed of residues conserved among RecJ proteins and is positively charged. These findings and the narrow width of the groove indicate that the groove binds single- instead of double-stranded DNA.

SUBMITTER: Yamagata A

PROVIDER: S-EPMC122875 | biostudies-literature | 2002 Apr

REPOSITORIES: biostudies-literature

ACCESS DATA

Json Xml

Publications

The crystal structure of exonuclease RecJ bound to Mn2+ ion suggests how its characteristic motifs are involved in exonuclease activity.

Yamagata Atsushi A Kakuta Yoshimitsu Y Masui Ryoji R Fukuyama Keiichi K

Proceedings of the National Academy of Sciences of the United States of America 20020423 9

RecJ, a 5' to 3' exonuclease specific for single-stranded DNA, functions in DNA repair and recombination systems. We determined the crystal structure of RecJ bound to Mn(2+) ion essential for its activity. RecJ has a novel fold in which two domains are interconnected by a long helix, forming a central groove. Mn(2+) is located on the wall of the groove and is coordinated by conserved residues characteristic of a family of phosphoesterases that includes RecJ proteins. The groove is composed of re ...[more]

PMID: 11972066

Similar Datasets

Mutational analysis of the RecJ exonuclease of Escherichia coli: identification of phosphoesterase motifs.

Project description:The recJ gene, identified in Escherichia coli, encodes a Mg(+2)-dependent 5'-to-3' exonuclease with high specificity for single-strand DNA. Genetic and biochemical experiments implicate RecJ exonuclease in homologous recombination, base excision, and methyl-directed mismatch repair. Genes encoding proteins with strong similarities to RecJ have been found in every eubacterial genome sequenced to date, with the exception of Mycoplasma and Mycobacterium tuberculosis. Multiple genes encoding proteins similar to RecJ are found in some eubacteria, including Bacillus and Helicobacter, and in the archaea. Among this divergent set of sequences, seven conserved motifs emerge. We demonstrate here that amino acids within six of these motifs are essential for both the biochemical and genetic functions of E. coli RecJ. These motifs may define interactions with Mg(2+) ions or substrate DNA. A large family of proteins more distantly related to RecJ is present in archaea, eubacteria, and eukaryotes, including a hypothetical protein in the MgPa adhesin operon of Mycoplasma, a domain of putative polyA polymerases in Synechocystis and Aquifex, PRUNE of Drosophila, and an exopolyphosphatase (PPX1) of Saccharomyces cereviseae. Because these six RecJ motifs are shared between exonucleases and exopolyphosphatases, they may constitute an ancient phosphoesterase domain now found in all kingdoms of life.

| S-EPMC103638 | biostudies-literature

Structure of RecJ exonuclease defines its specificity for single-stranded DNA.

Project description:RecJ is a single-stranded DNA (ssDNA)-specific 5'-3' exonuclease that plays an important role in DNA repair and recombination. To elucidate how RecJ achieves its high specificity for ssDNA, we determined the entire structures of RecJ both in a ligand-free form and in a complex with Mn(2+) or Mg(2+) by x-ray crystallography. The entire RecJ consists of four domains that form a molecule with an O-like structure. One of two newly identified domains had structural similarities to an oligonucleotide/oligosaccharide-binding (OB) fold. The OB fold domain alone could bind to DNA, indicating that this domain is a novel member of the OB fold superfamily. The truncated RecJ containing only the core domain exhibited much lower affinity for the ssDNA substrate compared with intact RecJ. These results support the hypothesis that these structural features allow specific binding of RecJ to ssDNA. In addition, the structure of the RecJ-Mn(2+) complex suggests that the hydrolysis reaction catalyzed by RecJ proceeds through a two-metal ion mechanism.

| S-EPMC2843225 | biostudies-literature

Role of RecJ-like protein with 5'-3' exonuclease activity in oligo(deoxy)nucleotide degradation.

Project description:RecJ-like proteins belonging to the DHH family have been proposed to function as oligoribonucleases and 3'-phosphoadenosine 5'-phosphate (pAp) phosphatases in bacteria and archaea, which do not have Orn (oligoribonuclease) and CysQ (pAp phosphatase) homologs. In this study, we analyzed the biochemical and physiological characterization of the RecJ-like protein TTHA0118 from Thermus thermophilus HB8. TTHA0118 had high enzymatic activity as an oligodeoxyribonucleotide- and oligoribonucleotide-specific exonuclease and as pAp phosphatase. The polarity of degradation was 5' to 3', in contrast to previous reports about Bacillus subtilis NrnA, a RecJ-like protein. TTHA0118 preferentially hydrolyzed short oligodeoxyribonucleotides and oligoribonucleotides, whereas the RecJ exonuclease from T. thermophilus HB8 showed no such length dependence on oligodeoxyribonucleotide substrates. An insertion mutation of the ttha0118 gene led to growth reduction in minimum essential medium. Added 5'-mononucleotides, nucleosides, and cysteine increased growth of the ttha0118 mutant in minimum essential medium. The RecJ-like protein Mpn140 from Mycoplasma pneumoniae M129, which cannot synthesize nucleic acid precursors de novo, showed similar biochemical features to TTHA0118. Furthermore, B. subtilis NrnA also hydrolyzed oligo(deoxy)ribonucleotides in a 5'-3' direction. These results suggested that these RecJ-like proteins act in recycling short oligonucleotides to mononucleotides and in controlling pAp concentrations in vivo.

| S-EPMC3024776 | biostudies-literature

RecJ 5' Exonuclease Digestion of Oligonucleotide Failure Strands: A "Green" Method of Trityl-On Purification.

Project description:Methods of error filtration and correction post-gene assembly are a major bottleneck in the synthetic biology pipeline. Current oligonucleotide purification strategies, including polyacrylamide gel electrophoresis and high-performance liquid chromatography, are often expensive and labor-intensive, give low mass recovery, and contain hazardous chemicals. To circumvent these limitations, we explored an enzymatic means of oligonucleotide purification using RecJ, which is the only known exonuclease to digest single-stranded DNA (ssDNA) in the 5' to 3' direction. As a potential application to remove failure strands generated in oligonucleotide synthesis, we found RecJ does not recognize the 5' dimethoxytrityl blocking group and could therefore be used to specifically target and digest unblocked failure strands. In combination with ssDNA binding protein (SSBP), which acts to recruit RecJ via C-terminal recognition, secondary structure formation is precluded, allowing for enhanced RecJ processivity. Using this method to purify crude trityl-on oligonucleotides, we also found on average 30 units of RecJ with 0.5 μg of SSBP digests 53 pmol of 5' hydroxylated ssDNA (60 min at 37 °C). With these parameters, the average purity is increased by 8%. As such, this novel method can be adapted to most laboratory practices, particularly those with DNA synthesis automation as a simple, inexpensive (<$4), and eco-friendly means of oligonucleotide trityl-on purification.

| S-EPMC8045232 | biostudies-literature

Crystal structure of truncated human apolipoprotein A-I suggests a lipid-bound conformation.

Project description:The structure of truncated human apolipoprotein A-I (apo A-I), the major protein component of high density lipoprotein, has been determined at 4-A resolution. The crystals comprise residues 44-243 (exon 4) of apo A-I, a fragment that binds to lipid similarly to intact apo A-I and that retains the lipid-bound conformation even in the absence of lipid. The molecule consists almost entirely of a pseudo-continuous, amphipathic alpha-helix that is punctuated by kinks at regularly spaced proline residues; it adopts a shape similar to a horseshoe of dimensions 125 x 80 x 40 A. Four molecules in the asymmetric unit associate via their hydrophobic faces to form an antiparallel four-helix bundle with an elliptical ring shape. Based on this structure, we propose a model for the structure of apo A-I bound to high density lipoprotein.

| S-EPMC24911 | biostudies-literature

Crystal structure of the NurA-dAMP-Mn2+ complex.

Project description:Generation of the 3' overhang is a critical event during homologous recombination (HR) repair of DNA double strand breaks. A 5'-3' nuclease, NurA, plays an important role in generating 3' single-stranded DNA during archaeal HR, together with Mre11-Rad50 and HerA. We have determined the crystal structures of apo- and dAMP-Mn(2)(+)-bound NurA from Pyrococcus furiousus (Pf NurA) to provide the basis for its cleavage mechanism. Pf NurA forms a pyramid-shaped dimer containing a large central channel on one side, which becomes narrower towards the peak of the pyramid. The structure contains a PIWI domain with high similarity to argonaute, endoV nuclease and RNase H. The two active sites, each of which contains Mn(2)(+) ion(s) and dAMP, are at the corners of the elliptical channel near the flat face of the dimer. The 3' OH group of the ribose ring is directed toward the channel entrance, explaining the 5'-3' nuclease activity of Pf NurA. We provide a DNA binding and cleavage model for Pf NurA.

| S-EPMC3300031 | biostudies-literature

Crystal Structure of the Human Copper Chaperone ATOX1 Bound to Zinc Ion.

Project description:The bioavailability of copper (Cu) in human cells may depend on a complex interplay with zinc (Zn) ions. We investigated the ability of the Zn ion to target the human Cu-chaperone Atox1, a small cytosolic protein capable of anchoring Cu(I), by a conserved surface-exposed Cys-X-X-Cys (CXXC) motif, and deliver it to Cu-transporting ATPases in the trans-Golgi network. The crystal structure of Atox1 loaded with Zn displays the metal ion bridging the CXXC motifs of two Atox1 molecules in a homodimer. The identity and location of the Zn ion were confirmed through the anomalous scattering of the metal by collecting X-ray diffraction data near the Zn K-edge. Furthermore, soaking experiments of the Zn-loaded Atox1 crystals with a strong chelating agent, such as EDTA, caused only limited removal of the metal ion from the tetrahedral coordination cage, suggesting a potential role of Atox1 in Zn metabolism and, more generally, that Cu and Zn transport mechanisms could be interlocked in human cells.

| S-EPMC9599288 | biostudies-literature

Characteristic motifs for families of allergenic proteins.

Project description:The identification of potential allergenic proteins is usually done by scanning a database of allergenic proteins and locating known allergens with a high sequence similarity. However, there is no universally accepted cut-off value for sequence similarity to indicate potential IgE cross-reactivity. Further, overall sequence similarity may be less important than discrete areas of similarity in proteins with homologous structure. To identify such areas, we first classified all allergens and their subdomains in the Structural Database of Allergenic Proteins (SDAP, http://fermi.utmb.edu/SDAP/) to their closest protein families as defined in Pfam, and identified conserved physicochemical property motifs characteristic of each group of sequences. Allergens populate only a small subset of all known Pfam families, as all allergenic proteins in SDAP could be grouped to only 130 (of 9318 total) Pfams, and 31 families contain more than four allergens. Conserved physicochemical property motifs for the aligned sequences of the most populated Pfam families were identified with the PCPMer program suite and catalogued in the webserver MotifMate (http://born.utmb.edu/motifmate/summary.php). We also determined specific motifs for allergenic members of a family that could distinguish them from non-allergenic ones. These allergen specific motifs should be most useful in database searches for potential allergens. We found that sequence motifs unique to the allergens in three families (seed storage proteins, Bet v 1, and tropomyosin) overlap with known IgE epitopes, thus providing evidence that our motif based approach can be used to assess the potential allergenicity of novel proteins.

| S-EPMC2631092 | biostudies-literature

Crystal structure of the bromide-bound D85S mutant of bacteriorhodopsin: principles of ion pumping.

Project description:We report the crystal structure of a bromide-bound form of the D85S mutant of bacteriorhodopsin, bR(D85S), a protein that uses light energy rather than ATP to pump halide ions across the cell membrane. Comparison of the structure of the halide-bound and halide-free states reveals that both displacements of individual side-chain positions and concerted helical movements occur on the extracellular side of the protein. Analysis of these structural changes reveals how this ion pump first facilitates ion uptake deep within the cell membrane and then prevents the backward escape of ions later in the pumping cycle. Together with the information provided by structures of intermediate states in the bacteriorhodopsin photocycle, this study also suggests the overall design principles that are necessary for ion pumping.

| S-EPMC1303101 | biostudies-literature

Apo, Zn2+-bound and Mn2+-bound structures reveal ligand-binding properties of SitA from the pathogen Staphylococcus pseudintermedius.

Project description:The Gram-positive bacterium Staphylococcus pseudintermedius is a leading cause of canine bacterial pyoderma, resulting in worldwide morbidity in dogs. S. pseudintermedius also causes life-threatening human infections. Furthermore, methicillin-resistant S. pseudintermedius is emerging, resembling the human health threat of methicillin-resistant Staphylococcus aureus. Therefore it is increasingly important to characterize targets for intervention strategies to counteract S. pseudintermedius infections. Here we used biophysical methods, mutagenesis, and X-ray crystallography, to define the ligand-binding properties and structure of SitA, an S. pseudintermedius surface lipoprotein. SitA was strongly and specifically stabilized by Mn2+ and Zn2+ ions. Crystal structures of SitA complexed with Mn2+ and Zn2+ revealed a canonical class III solute-binding protein with the metal cation bound in a cavity between N- and C-terminal lobes. Unexpectedly, one crystal contained both apo- and holo-forms of SitA, revealing a large side-chain reorientation of His64, and associated structural differences accompanying ligand binding. Such conformational changes may regulate fruitful engagement of the cognate ABC (ATP-binding cassette) transporter system (SitBC) required for metal uptake. These results provide the first detailed characterization and mechanistic insights for a potential therapeutic target of the major canine pathogen S. pseudintermedius, and also shed light on homologous structures in related staphylococcal pathogens afflicting humans.

| S-EPMC4242081 | 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