Biomaterial Database

Gapped Minicircles. A novel replication intermediate of kinetoplast DNA. 1984

P A Kitchin, and V A Klein, and B I Fein, and P T Englund

Kinetoplast DNA, the mitochondrial DNA in trypanosomatids, is a network of thousands of interlocked circles. Most of these circles are minicircles and a few are maxicircles. Minicircles replicate, after decatenation from the network, by a Cairns-type mechanism. The minicircle progeny then reattach to the network (Englund, P. T. (1979) J. Biol. Chem. 254, 4895-4900). We have now discovered a novel intermediate in Crithidia fasciculata minicircle replication. It is a highly gapped 2.5-kilobase free minicircle with nascent fragments of only 20 to 110 nucleotides. These fragments are nonligasable, and some remain nonligasable even after gap filling with DNA polymerase. Solution hybridization studies show that the nascent fragments are predominantly, if not exclusively, heavy strand.

UI	MeSH Term	Description	Entries
D007700	Kinetics	The rate dynamics in chemical or physical systems.
D008854	Microscopy, Electron	Microscopy using an electron beam, instead of light, to visualize the sample, thereby allowing much greater magnification. The interactions of ELECTRONS with specimens are used to provide information about the fine structure of that specimen. In TRANSMISSION ELECTRON MICROSCOPY the reactions of the electrons that are transmitted through the specimen are imaged. In SCANNING ELECTRON MICROSCOPY an electron beam falls at a non-normal angle on the specimen and the image is derived from the reactions occurring above the plane of the specimen.	Electron Microscopy
D008970	Molecular Weight	The sum of the weight of all the atoms in a molecule.	Molecular Weights,Weight, Molecular,Weights, Molecular
D009693	Nucleic Acid Hybridization	Widely used technique which exploits the ability of complementary sequences in single-stranded DNAs or RNAs to pair with each other to form a double helix. Hybridization can take place between two complimentary DNA sequences, between a single-stranded DNA and a complementary RNA, or between two RNA sequences. The technique is used to detect and isolate specific sequences, measure homology, or define other characteristics of one or both strands. (Kendrew, Encyclopedia of Molecular Biology, 1994, p503)	Genomic Hybridization,Acid Hybridization, Nucleic,Acid Hybridizations, Nucleic,Genomic Hybridizations,Hybridization, Genomic,Hybridization, Nucleic Acid,Hybridizations, Genomic,Hybridizations, Nucleic Acid,Nucleic Acid Hybridizations
D003421	Crithidia	A genus of parasitic protozoans found in the digestive tract of invertebrates, especially insects. Organisms of this genus have an amastigote and choanomastigote stage in their life cycle.	Crithidias
D004261	DNA Replication	The process by which a DNA molecule is duplicated.	Autonomous Replication,Replication, Autonomous,Autonomous Replications,DNA Replications,Replication, DNA,Replications, Autonomous,Replications, DNA
D004270	DNA, Circular	Any of the covalently closed DNA molecules found in bacteria, many viruses, mitochondria, plastids, and plasmids. Small, polydisperse circular DNA's have also been observed in a number of eukaryotic organisms and are suggested to have homology with chromosomal DNA and the capacity to be inserted into, and excised from, chromosomal DNA. It is a fragment of DNA formed by a process of looping out and deletion, containing a constant region of the mu heavy chain and the 3'-part of the mu switch region. Circular DNA is a normal product of rearrangement among gene segments encoding the variable regions of immunoglobulin light and heavy chains, as well as the T-cell receptor. (Riger et al., Glossary of Genetics, 5th ed & Segen, Dictionary of Modern Medicine, 1992)	Circular DNA,Circular DNAs,DNAs, Circular
D004591	Electrophoresis, Polyacrylamide Gel	Electrophoresis in which a polyacrylamide gel is used as the diffusion medium.	Polyacrylamide Gel Electrophoresis,SDS-PAGE,Sodium Dodecyl Sulfate-PAGE,Gel Electrophoresis, Polyacrylamide,SDS PAGE,Sodium Dodecyl Sulfate PAGE,Sodium Dodecyl Sulfate-PAGEs
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D018105	DNA, Kinetoplast	DNA of kinetoplasts which are specialized MITOCHONDRIA of trypanosomes and related parasitic protozoa within the order KINETOPLASTIDA. Kinetoplast DNA consists of a complex network of numerous catenated rings of two classes; the first being a large number of small DNA duplex rings, called minicircles, approximately 2000 base pairs in length, and the second being several dozen much larger rings, called maxicircles, approximately 37 kb in length.	Kinetoplast DNA,Kinetoplast DNA Maxicircles,Kinetoplast DNA Minicircles,kDNA,kDNA Maxicircles,kDNA Minicircles,DNA Maxicircles, Kinetoplast,DNA Minicircles, Kinetoplast,Maxicircles, Kinetoplast DNA,Maxicircles, kDNA,Minicircles, Kinetoplast DNA,Minicircles, kDNA