Mechanism of E. coli RecA protein directed strand exchanges in post-replication repair of DNA

Nature ◽  
1981 ◽  
Vol 294 (5842) ◽  
pp. 659-662 ◽  
Author(s):  
Stephen C. West ◽  
Era Cassuto ◽  
Paul Howard-Flanders
Keyword(s):  
Reca Protein ◽  
E Coli ◽  
Post Replication Repair

Electron Microscopy and image analysis of nucleo-protein complexes

1994 ◽  
Vol 52 ◽  
pp. 88-89
Author(s):  
E. H. Egelman ◽  
X. Yu
Keyword(s):  
Electron Microscopy ◽  
Image Analysis ◽  
Normal Cell ◽  
Genetic Recombination ◽  
Protein Complexes ◽  
Chromosomal Rearrangements ◽  
Reca Protein ◽  
E Coli ◽  
Helical Polymer ◽  
Specific Protease

The RecA protein of E. coli has been shown to mediate genetic recombination, regulate its own synthesis, control the expression of other genes, act as a specific protease, form a helical polymer and have an ATPase activity, among other observed properties. The unusual filament formed by the RecA protein on DNA has not previously been shown to exist outside of bacteria. Within this filament, the 36 Å pitch of B-form DNA is extended to about 95 Å, the pitch of the RecA helix. We have now establishedthat similar nucleo-protein complexes are formed by bacteriophage and yeast proteins, and availableevidence suggests that this structure is universal across all of biology, including humans. Thus, understanding the function of the RecA protein will reveal basic mechanisms, in existence inall organisms, that are at the foundation of general genetic recombination and repair.Recombination at this moment is assuming an importance far greater than just pure biology. The association between chromosomal rearrangements and neoplasms has become stronger and stronger, and these rearrangements are most likely products of the recombinatory apparatus of the normal cell. Further, damage to DNA appears to be a major cause of cancer.

Changes in protein composition of meiotic nodules during mammalian meiosis

1998 ◽  
Vol 111 (4) ◽  
pp. 413-423 ◽  
Author(s):  
A.W. Plug ◽  
A.H. Peters ◽  
K.S. Keegan ◽  
M.F. Hoekstra ◽  
P. de Boer ◽  
...  
Keyword(s):  
Dna Sequences ◽  
Protein A ◽  
Reca Protein ◽  
Protein Composition ◽  
Homologous Chromosomes ◽  
E Coli ◽  
Recombination Nodules ◽  
Chromosome Synapsis ◽  
Repair Protein ◽  
Mismatch Repair Protein

Homologous chromosome synapsis and meiotic recombination are facilitated by several meiosis-specific structures: the synaptonemal complex (SC), and two types of meiotic nodules: (1) early meiotic nodules (MNs), also called zygotene nodules or early recombination nodules, and (2) late recombination nodules (RNs). The former are thought to be nucleoprotein complexes involved in the check for homology preceding, or accompanying synapsis, while the latter have been shown to be involved in reciprocal recombination. We have examined by immunocytochemistry the meiotic localization of a series of proteins at sites along the asynapsed axial elements prior to homologous synapsis and at sites along the SCs following synapsis. Several of the proteins examined have been implicated in repair/recombination and include RAD51, a mammalian homolog of the Escherichia coli RecA protein; Replication Protein-A (RPA), a single-strand DNA binding protein; and MLH1, a mismatch repair protein which is a homolog of the E. coli MutL protein. In addition two proteins were examined that have been implicated in meiotic checkpoints: ATM, the protein mutated in the human disease Ataxia Telangiectasia, and ATR, another member of the same family of PIK kinases. We present evidence that these proteins are all components of meiotic nodules and document changes in protein composition of these structures during zygonema and pachynema of meiotic prophase in mouse spermatocytes. These studies support the supposition that a subset of MNs are converted into RNs. However, our data also demonstrate changes in protein composition within the context of early MNs, suggesting a differentiation of these nodules during the process of synapsis. The same changes in protein composition occurred on both the normal X axis, which has no homologous pairing partner in spermatocytes, and on the axes of aberrant chromosomes that nonhomologously synapse during synaptic adjustment. These findings suggest that DNA sequences associated with MNs still must undergo an obligatory processing, even in the absence of interactions between homologous chromosomes.

scholarly journals Exchange of DNA Base Pairs that Coincides with Recognition of Homology Promoted by E. coli RecA Protein

2004 ◽  
Vol 15 (6) ◽  
pp. 965-975 ◽  
Author(s):  
Ewa Folta-Stogniew ◽  
Shawn O'Malley ◽  
Ravindra Gupta ◽  
Karen S. Anderson ◽  
Charles M. Radding
Keyword(s):  
Reca Protein ◽  
Base Pairs ◽  
E Coli ◽  
Dna Base ◽  
Dna Base Pairs

scholarly journals RecA Protein from the Extremely Radioresistant Bacterium Deinococcus radiodurans: Expression, Purification, and Characterization

2002 ◽  
Vol 184 (6) ◽  
pp. 1649-1660 ◽  
Author(s):  
Jong-Il Kim ◽  
Ajay K. Sharma ◽  
Stephen N. Abbott ◽  
Elizabeth A. Wood ◽  
David W. Dwyer ◽  
...  
Keyword(s):  
Deinococcus Radiodurans ◽  
Atp Hydrolysis ◽  
Reca Protein ◽  
Strand Exchange ◽  
Exchange Reactions ◽  
Ssdna Binding ◽  
E Coli ◽  
Dna Strand Exchange ◽  
Ssdna Binding Protein ◽  
Dna Strand

ABSTRACT The RecA protein of Deinococcus radiodurans (RecADr) is essential for the extreme radiation resistance of this organism. The RecADr protein has been cloned and expressed in Escherichia coli and purified from this host. In some respects, the RecADr protein and the E. coli RecA (RecAEc) proteins are close functional homologues. RecADr forms filaments on single-stranded DNA (ssDNA) that are similar to those formed by the RecAEc. The RecADr protein hydrolyzes ATP and dATP and promotes DNA strand exchange reactions. DNA strand exchange is greatly facilitated by the E. coli SSB protein. As is the case with the E. coli RecA protein, the use of dATP as a cofactor permits more facile displacement of bound SSB protein from ssDNA. However, there are important differences as well. The RecADr protein promotes ATP- and dATP-dependent reactions with distinctly different pH profiles. Although dATP is hydrolyzed at approximately the same rate at pHs 7.5 and 8.1, dATP supports an efficient DNA strand exchange only at pH 8.1. At both pHs, ATP supports efficient DNA strand exchange through heterologous insertions but dATP does not. Thus, dATP enhances the binding of RecADr protein to ssDNA and the displacement of ssDNA binding protein, but the hydrolysis of dATP is poorly coupled to DNA strand exchange. The RecADr protein thus may offer new insights into the role of ATP hydrolysis in the DNA strand exchange reactions promoted by the bacterial RecA proteins. In addition, the RecADr protein binds much better to duplex DNA than the RecAEc protein, binding preferentially to double-stranded DNA (dsDNA) even when ssDNA is present in the solutions. This may be of significance in the pathways for dsDNA break repair in Deinococcus.

scholarly journals Functional Properties of Borrelia burgdorferi recA

2004 ◽  
Vol 186 (8) ◽  
pp. 2275-2280 ◽  
Author(s):  
Dionysios Liveris ◽  
Vishwaroop Mulay ◽  
Ira Schwartz
Keyword(s):  
Gene Expression ◽  
Borrelia Burgdorferi ◽  
Uv Irradiation ◽  
Reca Protein ◽  
Primary Role ◽  
Rapid Loss ◽  
E Coli ◽  
Uv Dose ◽  
Null Mutants

ABSTRACT Functions of the Borrelia burgdorferi RecA protein were investigated in Escherichia coli recA null mutants. Complementation with B. burgdorferi recA increased survival of E. coli recA mutants by 3 orders of magnitude at a UV dose of 2,000 μJ/cm2. The viability at this UV dose was about 10% that provided by the homologous recA gene. Expression of B. burgdorferi recA resulted in survival of E. coli at levels of mitomycin C that were lethal to noncomplemented hosts. B. burgdorferi RecA was as effective as E. coli RecA in mediating homologous recombination in E. coli. Furthermore, E. coli λ phage lysogens complemented with B. burgdorferi recA produced phage even in the absence of UV irradiation. The level of phage induction was 55-fold higher than the level in cells complemented with the homologous recA gene, suggesting that B. burgdorferi RecA may possess an enhanced coprotease activity. This study indicates that B. burgdorferi RecA mediates the same functions in E. coli as the homologous E. coli protein mediates. However, the rapid loss of viability and the absence of induction in recA expression after UV irradiation in B. burgdorferi suggest that recA is not involved in the repair of UV-induced damage in B. burgdorferi. The primary role of RecA in B. burgdorferi is likely to be a role in some aspect of recombination.

Ordered Intracellular Reca-Dna Assemblies

2000 ◽  
Vol 6 (S2) ◽  
pp. 860-861
Author(s):  
S. G. Wolf ◽  
S. Levin-Zaidman ◽  
D. Frenkiel-Krispin ◽  
E. Shimoni ◽  
I. Sabanay ◽  
...  
Keyword(s):  
Dna Damage ◽  
Dna Repair ◽  
Electron Micrographs ◽  
Reca Protein ◽  
Sos Response ◽  
Structural Features ◽  
Wild Type ◽  
E Coli ◽  
Dna Damaging Agents

The inducible SOS response increases the ability of bacteria to cope with DNA damage through various DNA repair processes in which the RecA protein plays a central role. We find that induction of the SOS system in wild-type E. coli bacteria results in fast and massive intracellular coaggregation of RecA and DNA into lateral assemblies, which comprise substantial portions of both the cellular RecA and the DNA complement. The structural features of the coaggregates and their relation to in-vitro RecA-DNA are consistent with the possibility that the intracellular assemblies represent a functional entity in which RecA-mediated DNA repair and protection activities occur.Bacterial chromatin is demarcated in electron micrographs of metabolically active cells as amorphous ribosome-free spaces that are irregularly spread over the cytoplasm (Fig. A). Wild-type E. coli cells exposed to DNA-damaging agents that induce the SOS response reveal a strikingly different morphology (Fig. B).

scholarly journals E. coli recA protein possesses a strand separating activity on short duplex DNAs.

1985 ◽  
Vol 4 (11) ◽  
pp. 3025-3030 ◽  
Author(s):  
M. Bianchi ◽  
B. Riboli ◽  
G. Magni
Keyword(s):  
Reca Protein ◽  
E Coli

scholarly journals Bacterial RecA Protein Promotes Adenoviral Recombination duringIn VitroInfection

mSphere ◽  
2018 ◽  
Vol 3 (3) ◽  
Author(s):  
Jeong Yoon Lee ◽  
Ji Sun Lee ◽  
Emma C. Materne ◽  
Rahul Rajala ◽  
Ashrafali M. Ismail ◽  
...  
Keyword(s):  
Homologous Recombination ◽  
Hot Spots ◽  
Genetic Recombination ◽  
Reca Protein ◽  
Human Adenovirus ◽  
Penton Base ◽  
Content Type ◽  
E Coli ◽  
Recombination Hot Spots ◽  
Loop 2

ABSTRACTAdenovirus infections in humans are common and sometimes lethal. Adenovirus-derived vectors are also commonly chosen for gene therapy in human clinical trials. We have shown in previous work that homologous recombination between adenoviral genomes of human adenovirus species D (HAdV-D), the largest and fastest growing HAdV species, is responsible for the rapid evolution of this species. Because adenovirus infection initiates in mucosal epithelia, particularly at the gastrointestinal, respiratory, genitourinary, and ocular surfaces, we sought to determine a possible role for mucosal microbiota in adenovirus genome diversity. By analysis of known recombination hot spots across 38 human adenovirus genomes in species D (HAdV-D), we identified nucleotide sequence motifs similar to bacterial Chi sequences, which facilitate homologous recombination in the presence of bacterial Rec enzymes. These motifs, referred to here as ChiAD, were identified immediately 5′ to the sequence encoding penton base hypervariable loop 2, which expresses the arginine-glycine-aspartate moiety critical to adenoviral cellular entry. Coinfection with two HAdV-Ds in the presence of anEscherichia colilysate increased recombination; this was blocked in a RecA mutant strain,E. coliDH5α, or upon RecA depletion. Recombination increased in the presence ofE. colilysate despite a general reduction in viral replication. RecA colocalized with viral DNA in HAdV-D-infected cell nuclei and was shown to bind specifically to ChiADsequences. These results indicate that adenoviruses may repurpose bacterial recombination machinery, a sharing of evolutionary mechanisms across a diverse microbiota, and unique example of viral commensalism.IMPORTANCEAdenoviruses are common human mucosal pathogens of the gastrointestinal, respiratory, and genitourinary tracts and ocular surface. Here, we report finding Chi-like sequences in adenovirus recombination hot spots. Adenovirus coinfection in the presence of bacterial RecA protein facilitated homologous recombination between viruses. Genetic recombination led to evolution of an important external feature on the adenoviral capsid, namely, the penton base protein hypervariable loop 2, which contains the arginine-glycine-aspartic acid motif critical to viral internalization. We speculate that free Rec proteins present in gastrointestinal secretions upon bacterial cell death facilitate the evolution of human adenoviruses through homologous recombination, an example of viral commensalism and the complexity of virus-host interactions, including regional microbiota.

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