Oligonucleotide-mediated multiplex genome engineering is an important tool for bacterial genome editing. The efficient application of this technique requires the inactivation of the endogenous methyl-directed mismatch repair system that in turn leads to a drastically elevated genomic mutation rate and the consequent accumulation of undesired off-target mutations. Here, we present a novel strate...

DNA duplexes with or without mismatches and with or without adenine-methylated GATC sequences were prepared from separated strands of bacteriophage A DNA and used to transfect Escherichia cofi. Unmethylated heteroduplexes containing one or more repairable mismatches transfect cells with a functioning mismatch repair system less efficiently than they transfect cells deficient in mismatch repair....

CTG•CAG repeat expansions cause at least twelve inherited neurological diseases. Expansions require the presence, not the absence, of the mismatch repair protein MutSβ (Msh2-Msh3 heterodimer). To evaluate properties of MutSβ that drive expansions, previous studies have tested under-expression, ATPase function or polymorphic variants of Msh2 and Msh3, but in disparate experimental systems. Addit...

Oligonucleotide-mediated multiplex genome engineering is an important tool for bacterial genome editing. The efficient application of this technique requires the inactivation of the endogenous methyl-directed mismatch repair system that in turn leads to a drastically elevated genomic mutation rate and the consequent accumulation of undesired off-target mutations. Here, we present a novel strate...

1. DNA Damage 1.1. Spontaneous Alterations of DNA (by Mutator Genes) 1.2. Environmental Damage to DNA 2. DNA Repair by Reversal of Damage Without Excision 2.1. Photoreactivation 2.2. Repair of O-Alkylguanine and Alkylthymine Without DNA trand Excision 3. Base Excision Repair in Non-Mammalian Cells 3.1. DNA Glycosylase in Non-Mammalian Cells 4. Base Excision Repair in Mammalian Cells 4.1. DNA Gl...

Defective mismatch repair (MMR) in humans is associated with colon cancer and instability of microsatellites, that is, DNA sequences with one or several nucleotides repeated. Key factors of eukaryotic MMR are the heterodimers MutSα (Msh2-Msh6), which recognizes base-base mismatches and unpaired nucleotides in DNA, and MutLα (Mlh1-Pms1), which facilitates downstream steps. In addition, MutSβ (Ms...

GTBP is one of the functional homologues of the bacterial mismatch repair gene mutS, whose product forms a heterodimer with hMSH2 to bind to the mismatched region of double-stranded DNA. We determined the expression of the GTBP gene and found that two forms of the transcripts were ubiquitously expressed in normal human tissues. These transcripts, termed GTBP-N and GTBP-ALT, were generated by th...

Yeast Msh2p forms complexes with Msh3p and Msh6p to repair DNA mispairs that arise during DNA replication. In addition to their role in mismatch repair (MMR), the MSH2 and MSH3 gene products are required to remove 3' nonhomologous DNA tails during genetic recombination. The mismatch repair genes MSH6, MLH1, and PMS1, whose products interact with Msh2p, are not required in this process. We have ...

The correction of disease-causing mutations by single-strand oligonucleotide-templated DNA repair (ssOR) is an attractive approach to gene therapy, but major improvements in ssOR efficiency and consistency are needed. The mechanism of ssOR is poorly understood but may involve annealing of oligonucleotides to transiently exposed single-stranded regions in the target duplex. In bacteria and yeast...

Mismatch (MMR) repair system plays a significant role in restoration of stability in the genome. Mutations in mismatch repair genes hamper their activity thus bring about a defect in mismatch repair (MMR) mechanism thereby conferring instability in the microsatellite sequences of both the coding and non-coding regions of the genome. Mutated mismatch repair genes result in the expansion or contr...