Biomaterial Database

Sequence specificity of DNA-psoralen photoproduct formation in supercoiled plasmid DNA (pUC19). 1995

L Kittler, and G Löber

Institut für Molekulare Biotechnologie e.V., Jena, Germany.

Supercoiled pUC19 DNA, photoreacted with psoralen derivatives (xanthotoxin (8-methoxypsoralen, 8-MOP), 4,5',8-trimethylpsoralen (TMP) and angelicin), influences the enzymatic activity of restriction enzymes in a different manner, although all the enzymes employed contain, within their recognition sites, suitable nucleic acid bases for photoproduct formation. The activity of the enzymes is strongly influenced by the photomodification of thymine residues within their recognition sites. 5'-TpA sequences favour intercalation as an essential prerequisite of the photoreaction, while 5'ApT sequences do not. This, in turn, influences photoproduct formation and the inhibition of the action of the restriction enzymes KpnI, SspI, DraI and RsaI, but not EcoRI and BamHI. The inhibitory effect is independent of the number of cleavage sites and also of whether monoaddition products or crosslinks are formed. Psoralen intercalation alone does not affect the activity of the restriction enzymes used.

UI	MeSH Term	Description	Entries
D007364	Intercalating Agents	Agents that are capable of inserting themselves between the successive bases in DNA, thus kinking, uncoiling or otherwise deforming it and therefore preventing its proper functioning. They are used in the study of DNA.	Intercalating Agent,Intercalating Ligand,Intercalative Compound,Intercalator,Intercalators,Intercalating Ligands,Intercalative Compounds,Agent, Intercalating,Agents, Intercalating,Compound, Intercalative,Compounds, Intercalative,Ligand, Intercalating,Ligands, Intercalating
D008730	Methoxsalen	A naturally occurring furocoumarin compound found in several species of plants, including Psoralea corylifolia. It is a photoactive substance that forms DNA ADDUCTS in the presence of ultraviolet A irradiation.	8-Methoxypsoralen,Ammoidin,Xanthotoxin,8-MOP,Deltasoralen,Dermox,Geroxalen,Meladinina,Meladinine,Meloxine,Methoxa-Dome,Méladinine,Oxsoralen,Oxsoralen-Ultra,Puvalen,Ultramop,8 MOP,8 Methoxypsoralen,8MOP,Methoxa Dome,Oxsoralen Ultra
D008969	Molecular Sequence Data	Descriptions of specific amino acid, carbohydrate, or nucleotide sequences which have appeared in the published literature and/or are deposited in and maintained by databanks such as GENBANK, European Molecular Biology Laboratory (EMBL), National Biomedical Research Foundation (NBRF), or other sequence repositories.	Sequence Data, Molecular,Molecular Sequencing Data,Data, Molecular Sequence,Data, Molecular Sequencing,Sequencing Data, Molecular
D010957	Plasmids	Extrachromosomal, usually CIRCULAR DNA molecules that are self-replicating and transferable from one organism to another. They are found in a variety of bacterial, archaeal, fungal, algal, and plant species. They are used in GENETIC ENGINEERING as CLONING VECTORS.	Episomes,Episome,Plasmid
D011564	Furocoumarins	Polycyclic compounds consisting of a furan ring fused with coumarin. They commonly occur in PLANTS, especially UMBELLIFERAE and RUTACEAE, as well as PSORALEA.	Furanocoumarin,Furanocoumarins,Furocoumarin,Psoralens,Angelicins
D004262	DNA Restriction Enzymes	Enzymes that are part of the restriction-modification systems. They catalyze the endonucleolytic cleavage of DNA sequences which lack the species-specific methylation pattern in the host cell's DNA. Cleavage yields random or specific double-stranded fragments with terminal 5'-phosphates. The function of restriction enzymes is to destroy any foreign DNA that invades the host cell. Most have been studied in bacterial systems, but a few have been found in eukaryotic organisms. They are also used as tools for the systematic dissection and mapping of chromosomes, in the determination of base sequences of DNAs, and have made it possible to splice and recombine genes from one organism into the genome of another. EC 3.21.1.	Restriction Endonucleases,DNA Restriction Enzyme,Restriction Endonuclease,Endonuclease, Restriction,Endonucleases, Restriction,Enzymes, DNA Restriction,Restriction Enzyme, DNA,Restriction Enzymes, DNA
D004278	DNA, Superhelical	Circular duplex DNA isolated from viruses, bacteria and mitochondria in supercoiled or supertwisted form. This superhelical DNA is endowed with free energy. During transcription, the magnitude of RNA initiation is proportional to the DNA superhelicity.	DNA, Supercoiled,DNA, Supertwisted,Supercoiled DNA,Superhelical DNA,Supertwisted DNA
D001483	Base Sequence	The sequence of PURINES and PYRIMIDINES in nucleic acids and polynucleotides. It is also called nucleotide sequence.	DNA Sequence,Nucleotide Sequence,RNA Sequence,DNA Sequences,Base Sequences,Nucleotide Sequences,RNA Sequences,Sequence, Base,Sequence, DNA,Sequence, Nucleotide,Sequence, RNA,Sequences, Base,Sequences, DNA,Sequences, Nucleotide,Sequences, RNA
D013379	Substrate Specificity	A characteristic feature of enzyme activity in relation to the kind of substrate on which the enzyme or catalytic molecule reacts.	Specificities, Substrate,Specificity, Substrate,Substrate Specificities
D014307	Trioxsalen	Pigmenting photosensitizing agent obtained from several plants, mainly Psoralea corylifolia. It is administered either topically or orally in conjunction with ultraviolet light in the treatment of vitiligo.	Trimethylpsoralen,Trioxysalen,2,5,9-Trimethyl-7H-furo(3,2-g)benzopyran-7-one,4,5',8-Trimethylpsoralen,NSC-71047,Trioxisalenum,Trisoralen,NSC 71047,NSC71047