Biochemical Properties of MutL, a DNA Mismatch Repair Endonuclease

Fukui, Kenji; Shimada, Atsuhiro; Iino, Hitoshi; Masui, Ryoji; Kuramitsu, Seiki

doi:10.5772/23758

Cited by 4 publications

(9 citation statements)

References 83 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…To determine which functional region(s) of MutL ( Fukui et al, 2011 ; Guarne, 2012 ; Banasik and Sachadyn, 2014 ; Guarne and Charbonnier, 2015 ) are involved in recombinational switching at vlsE , we generated chromosomal mutL mutants in the endogenous mutL locus, with specific changes in motifs of the protein predicted to be involved in adenosine triphosphate (ATP) binding, ATP hydrolysis, endonuclease activity, or in the β-clamp binding motif. The mutations introduced were based upon MutL mutations that affected mismatch repair in the MutL prototype from Bacillus subtilis ( Pillon et al, 2010 , 2011 ; Bolz et al, 2012 ).…”

Section: Resultsmentioning

confidence: 99%

The Putative Endonuclease Activity of MutL Is Required for the Segmental Gene Conversion Events That Drive Antigenic Variation of the Lyme Disease Spirochete

et al. 2022

View full text Add to dashboard Cite

The Lyme disease spirochete Borrelia burgdorferi, encodes an elaborate antigenic variation system that promotes the ongoing variation of a major surface lipoprotein, VlsE. Changes in VlsE are continual and always one step ahead of the host acquired immune system, which requires 1–2 weeks to generate specific antibodies. By the time this happens, new VlsE variants have arisen that escape immunosurveillance, providing an avenue for persistent infection. This antigenic variation system is driven by segmental gene conversion events that transfer information from a series of silent cassettes (vls2-16) to the expression locus, vlsE. The molecular details of this process remain elusive. Recombinational switching at vlsE is RecA-independent and the only required factor identified to date is the RuvAB branch migrase. In this work we have used next generation long-read sequencing to analyze the effect of several DNA replication/recombination/repair gene disruptions on the frequency of gene conversions at vlsE and report a requirement for the mismatch repair protein MutL. Site directed mutagenesis of mutL suggests that the putative MutL endonuclease activity is required for recombinational switching at vlsE. This is the first report of an unexpected essential role for MutL in a bacterial recombination system and expands the known function of this protein as well as our knowledge of the details of the novel recombinational switching mechanism for vlsE variation.

show abstract

Section: Resultsmentioning

confidence: 99%

The Putative Endonuclease Activity of MutL Is Required for the Segmental Gene Conversion Events That Drive Antigenic Variation of the Lyme Disease Spirochete

et al. 2022

View full text Add to dashboard Cite

show abstract

“…A caveat in our experiments is that additional factor(s) might be required for the β clamp and clamp loader to confer strand specificity to the MutL endonuclease. Although such a possibility needs to be carefully examined in the future, at this point we favor the possibility that ttMutL is not activated by the β clamp, because ttMutL lacks the β‐clamp‐interacting motif that is conserved among most bacterial MutL homologs . If this is the case, an as yet unidentified mechanism might be involved in determining the strand to be repaired in T. thermophilus .…”

Section: Discussionmentioning

confidence: 99%

“…S8). Because the β clamp‐interaction motif is hardly found in the amino acid sequence of ttMutL , it can be suspected that the observed coimmunoprecipitation of β clamp with ttMutL reflects their indirect interaction that is mediated by ttMutS. It is known that MutS interacts with both MutL and β clamp, therefore anti‐ttMutL Ig may catch the ttMutS–β clamp complex.…”

Section: Discussionmentioning

confidence: 99%

“…To analyze the function of the N-terminal ATPase domain of ttMutL, we constructed an NTD deletion mutant, leaving only the C-terminal domain (CTD) of ttMutL. It has been reported that the NTD has MutSinteracting region [54], and the CTD contains endonuclease motifs and is sufficient for the endonuclease activity [2,13,15,[29][30][31] (Fig. S13).…”

Section: No Stimulation Was Detected In the Ntd-deleted Mutant Of Ttmutlmentioning

confidence: 99%

“…MutS and other MMR proteins direct MutLα to cleave the error‐containing strand . MutS and MutL homodimers whose fundamental properties are similar to those of eukaryotic MutSα and MutLα are conserved in the majority of bacteria except for a few species, including Escherichia coli . The E. coli ‐type MMR is characterized by a lack of endonuclease activity in MutL.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

MutS stimulates the endonuclease activity of MutL in an ATP‐hydrolysis‐dependent manner

et al. 2013

Self Cite

View full text Add to dashboard Cite

In the initial steps of DNA mismatch repair, MutS recognizes a mismatched base and recruits the latent endonuclease MutL onto the mismatch-containing DNA in concert with other proteins. MutL then cleaves the error-containing strand to introduce an entry point for the downstream excision reaction. Because MutL has no intrinsic ability to recognize a mismatch and discriminate between newly synthesized and template strands, the endonuclease activity of MutL is strictly regulated by ATP-binding in order to avoid nonspecific degradation of the genomic DNA. However, the activation mechanism for its endonuclease activity remains unclear. In this study, we found that the coexistence of a mismatch, ATP and MutS unlocks the ATP-binding-dependent suppression of MutL endonuclease activity. Interestingly, ATPase-deficient mutants of MutS were unable to activate MutL. Furthermore, wild-type MutS activated ATPase-deficient mutants of MutL less efficiently than wild-type MutL. We concluded that ATP hydrolysis by MutS and MutL is involved in the mismatch-dependent activation of MutL endonuclease activity.

show abstract

Destabilization of the MutSα’s protein-protein interface due to binding to the DNA adduct induced by anticancer agent carboplatin via molecular dynamics simulations

Negureanu

Salsbury

2013

J Mol Model

View full text Add to dashboard Cite

DNA mismatch repair (MMR) proteins maintain genetic integrity in all organisms by recognizing and repairing DNA errors. Such alteration of hereditary information can lead to various diseases, including cancer. Besides their role in DNA repair, MMR proteins detect and initiate cellular responses to certain type of DNA damage. Its response to the damaged DNA has made the human MMR pathway a useful target for anticancer agents such as carboplatin. This study indicates that strong, specific interactions at the interface of MutSα in response to the mismatched DNA recognition are replaced by weak, non-specific interactions in response to the damaged DNA recognition. Data suggest a severe impairment of the dimerization of MutSα in response to the damaged DNA recognition. While the core of MutSα is preserved in response to the damaged DNA recognition, the loss of contact surface and the rearrangement of contacts at the protein interface suggest a different packing in response to the damaged DNA recognition. Coupled in response to the mismatched DNA recognition, interaction energies, hydrogen bonds, salt bridges, and solvent accessible surface areas at the interface of MutSα and within the subunits are uncoupled or asynchronously coupled in response to the damaged DNA recognition. These pieces of evidence suggest that the loss of a synchronous mode of response in the MutSα’s surveillance for DNA errors would possible be one of the mechanism(s) of signaling the MMR-dependent programed cell death much wanted in anticancer therapies. The analysis was drawn from dynamics simulations.

show abstract

Biochemical Properties of MutL, a DNA Mismatch Repair Endonuclease

Cited by 4 publications

References 83 publications

The Putative Endonuclease Activity of MutL Is Required for the Segmental Gene Conversion Events That Drive Antigenic Variation of the Lyme Disease Spirochete

The Putative Endonuclease Activity of MutL Is Required for the Segmental Gene Conversion Events That Drive Antigenic Variation of the Lyme Disease Spirochete

MutS stimulates the endonuclease activity of MutL in an ATP‐hydrolysis‐dependent manner

Destabilization of the MutSα’s protein-protein interface due to binding to the DNA adduct induced by anticancer agent carboplatin via molecular dynamics simulations

Contact Info

Product

Resources

About