Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:6.5.1.2 (DNA ligase)
 2,749 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We describe a PCR-based approach for the synthesis of circularizable ligation probes (CLiPs). CLiPs are single-stranded probes that consist of target-specific ends separated by a noncomplementary "linker" sequence. When hybridized to a target, the CLiP forms a nicked circle that may be sealed by DNA ligase only if the 5' and 3' ends show perfect Watson-Crick base pairing, thus enabling the discrimination of single nucleotide polymorphisms. Primers incorporating target sequence at their 5' end and plasmid sequence at the 3' end were used in a PCR amplification. In addition, the antisense primer was 5' labeled with biotin, and the amplification was performed in the presence of fluorescently labeled dUTP. The resulting PCR product was captured with streptavidin-coated paramagnetic beads, and the top strand, which forms the CLiP, was alkali eluted. This PCR-based method has allowed the synthesis of CLiPs that are larger and more highly labeled than has previously been possible, with ligation efficiencies similar to those of the purest chemically synthesized padlock probes. Ligations performed in the presence of cognate or mismatched sequence were analyzed by denaturing PAGE using a fluorescent DNA sequencer. Genotyping using target immobilized to nylon membranes was also performed. The CLiPs were readily able to distinguish between mutant and wild-type alleles for the common genetic disorder, 21-hydroxylase deficiency. Additionally, CLiPs of different lengths were synthesized and compared.
 ...
PMID:Synthesis and application of circularizable ligation probes. 1125 94

Bloom Syndrome (BS, MIM #210900) is an autosomal recessive genetic disorder caused by a mutation in the BLM gene, which codes for the DNA repair enzyme RecQL3 helicase. Without proper DNA repair mechanisms, abnormal DNA exchange takes place between sister chromatids and results in genetic instability that may lead to cancer, especially lymphoma and acute myelogenous leukemia, lower and upper gastrointestinal tract neoplasias, cutaneous tumors, and neoplasias in the genitalia and urinary tract. BS patients are usually of Ashkenazi Jewish descent and exhibit narrow facial features, elongated limbs, and several dermatologic complications including photosensitivity, poikiloderma, and telangiectatic erythema. The most concerning manifestation of BS is multiple malignancies, which require frequent screenings and strict vigilance by the physician. Therefore, distinguishing between BS and other dermatologic syndromes of similar presentation such as Rothmund-Thomson Syndrome, Erythropoietic Protoporphyria, and Cockayne Syndrome is paramount to disease management and to prolonging life. BS can be diagnosed through a variety of DNA sequencing methods, and genetic testing is available for high-risk populations. This review consolidates several sources on BS sequelae and aims to suggest the importance of differentiating BS from other dermatologic conditions. This paper also elucidates the recently discovered BRAFT and FANCM protein complexes that link BS and Fanconi anemia.
...
PMID:Bloom syndrome. 2460 44