Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.1.30.2 (endonuclease)
 18,621 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The biological processing of thymine ring saturation and fragmentation products is summarized in Table 1. The ring saturation product, thymine glycol, is a block to in vitro DNA synthesis, whereas the ring saturation product, dihydrothymine, is not. Both these lesions are recognized in vitro by endonucleases III and VIII. Since thymine glycol is a replicative block, it is a lethal lesion in vivo. The excision repair process for removal of thymine glycols from DNA is initiated in vivo by endonuclease III and is followed by the action of either exonuclease III or endonuclease IV. Thymine glycol is very efficiently bypassed by translesion bypass in both single and double stranded DNA, however, because thymine glycol templates an adenine (A) and retains pairing characteristics, it is at best a weakly mutagenic lesion. The thymine ring fragmentation product, urea, and apurinic/apyrimidinic (AP) sites are both strong blocks to in vitro DNA synthesis. Both are substrates in vitro for endonucleases III, IV, VIII and IX as well as exonuclease III. Both are lethal lesions in single stranded and double stranded phage transfecting DNA. The excision repair of urea residues and AP sites is initiated in vivo by either exonuclease III or endonuclease IV. Neither of these noninstructive lesions are efficiently bypassed by UV-induced translesion bypass, however, when bypass occurs mutations result. beta-ureidoisobutylic acid is also a block to DNA synthesis in vitro. DNA containing this lesion is a substrate for endonucleases VIII and IX. The biological processing of this ring open thymine fragmentation product has yet to be determined. Thus, these ring saturation and fragmentation products of thymine have provided a point of departure for understanding the biological processing of modified bases with altered pairing and/or stacking properties.
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PMID:Processing of ring saturation and fragmentation products of DNA thymine in Escherichia coli. 266

Thymine auxotrophs of Bacillus subtilis strains lysogenic for temperate bacteriophage SP beta c2 were transformed to prototrophy by DNA from related phage phi 3T. During transformation, the phi 3T-encoded thymidylate synthetase gene, thyP3, became integrated into the extreme right end of the SP beta c2 prophage near the bacterial citK gene. Upon heat induction, the transformed B. subtilis cells released SP beta c2T phages that could lysogenize thymine auxotrophs and convert them to prototrophy. Comparison of restriction endonuclease fragments of DNAs from SP beta c2 and SP beta c2T phages revealed that the latter contained a large region of deletion and substitution near the center of the chromosome. This region included the phage attachment site on the SP beta c2 genome.
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PMID:Genome organization of Sp beta c2 bacteriophage carrying the thyP3 gene. 631 59

We studied the genetic basis of familial neurohypophyseal diabetes insipidus in a Japanese family. The members had polyuria and a deficiency of plasma vasopressin (AVP). Polymerase chain reaction (PCR) amplified exons of the AVP-neurophysin-II gene were subcloned and sequenced. Exons 1 and 3 were normal, but nucleotide 1884 Guanine (G) in exon 2 was substituted with Thymine (T), which induced a substitution of glycine (Gly) for valine (Val). To examine the presence of this mutation in the affected subjects, we designed two mutated primers. One of them induced a new endonuclease restriction site in the PCR fragments from normal, and the other induced a new endonuclease restriction site from patients with the mutation. DNA fragments from two affected members of this family were amplified with this primer, and the PCR products were digested by endonuclease and resolved by electrophoresis. The results indicated that these subjects had both normal and mutant alleles, indicating that the mutation was heterozygous. We concluded that this mutation caused neurohypophyseal diabetes insipidus in this family.
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PMID:A new type of familial central diabetes insipidus caused by a single base substitution in the neurophysin II coding region of the vasopressin gene. 862 36

DNA repair in chromatin is subject to topological constraints, suggesting a requirement for chromatin modification and remodeling activities. Thymine DNA glycosylase (TDG) initiates repair of G/T and G/U mismatches, commonly associated with CpG islands, by removing thymine and uracil moieties. We report that TDG associates with transcriptional coactivators CBP and p300 and that the resulting complexes are competent for both the excision step of repair and histone acetylation. Furthermore, TDG stimulates CBP transcriptional activity in transfected cells and reciprocally serves as a substrate for CBP/p300 acetylation. Remarkably, this acetylation triggers release of CBP from DNA ternary complexes and also regulates recruitment of repair endonuclease APE. These observations reveal a potential regulatory role for protein acetylation in base mismatch repair and a role for CBP/p300 in maintaining genomic stability.
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PMID:Association of CBP/p300 acetylase and thymine DNA glycosylase links DNA repair and transcription. 1186 1