sequence

Y chromosome

...ng genes important for male fertility. Most of the sequence pairs are greater than 99.97 percent identical. Th... of the human Y chromosome is a mosaic of discrete sequence classes. Nature, 423, 825-837 Rozen, S., et. al. (2003) Abundant gene conversion between arms of p...

Unsolved problems in biology

... into? Given a particular desired shape, what DNA sequence will produce it ? What are all the functions of the DNA? Other than the structural genes, which is the simpler part of the system? What is the complete structure and function of the proteome proteins expressed by a cell or organ at a particul...

Transmembrane protein

...transmembrane proteins have an internal topogenic sequence . Types There are two basic types of transmembrane proteins: Single-pass Multi-pass transmembrane proteins have multiple topogenic sequences . Examples Some cell adhesion proteins Some receptor proteins Glycophorin Insulin rece...

Tobacco mosaic virus

...ucleotides per protein monomer. The amino acid sequence of TMV's coat protein has been published in "American Chemical Society's Chemical Abstracts" in 1972 as a single word, Acetylseryltyrosylserylisol...serine , which supposedly is the longest word in the English language . In plants, tobacco mosaic ...

Trait

...equence; the slightly different variations of that sequence are called alleles. Alleles can be significantly different and produce different product RNAs . Combinations of different alleles thus go on to generate different traits through the information flow charted above. For example, if the allele...

Tobacco mosaic virus

...ucleotides per protein monomer. The amino acid sequence of TMV's coat protein has been published in "American Chemical Society's Chemical Abstracts" in 1972 as a single word, Acetylseryltyrosylserylisol...serine , which supposedly is the longest word in the English language . In plants, tobacco mosaic ...

Tertiary structure

...native conformation of a protein from its primary sequence . Conventionally, tertiary structures are deduced through crystallography or multidimensional NMR . The study of protein tertiary structure is known as structural biology . See also: primary structure -- secondary structure -- quaternary s...

Endoplasmic reticulum

...rked with an address tag that are called a signal sequence . Gnter Blobel was awarded the 1999 Nobel Prize in Physiology or Medicine for his discovery of these signal sequences in 1975. The N-terminus (one end) of a polypeptide chain (e.g., a protein) contains a few amino acids that work as an addr...

Signal transduction

...referred to as signal transduction often involve a sequence of biochemical reactions inside the cell, whic... to as " genetic programs ," one example being the sequence of events that take place when an egg is fertilized by a sperm . Types of signals Extrace...

Sequencing

...results in a symbolic linear depiction known as a sequence which succinctly summarizes much of the atomic-le...ies to have been devised to scale the method up to sequence genes and genome. Two of the mainstream chain termination strategies are chromosome walking and...

Endoplasmic reticulum

...rked with an address tag that are called a signal sequence . Gnter Blobel was awarded the 1999 Nobel Prize in Physiology or Medicine for his discovery of these signal sequences in 1975. The N-terminus (one end) of a polypeptide chain (e.g., a protein) contains a few amino acids that work as an addr...

Endoplasmic reticulum

...rked with an address tag that are called a signal sequence . Gnter Blobel was awarded the 1999 Nobel Prize in Physiology or Medicine for his discovery of these signal sequences in 1975. The N-terminus (one end) of a polypeptide chain (e.g., a protein) contains a few amino acids that work as an addr...

RNA

...because it logically has the equivalent nucleotide sequence of the new RNA strand). A small stretch of DNA-RN...nzyme. The synthesis continues until a termination sequence is reached. The resulting RNA molecule is the primary transcript . Modulation of the rate of initia...

Reverse genetics

...r information about them. To learn the influence a sequence has on phenotype, or to discover its biological function, researchers may engineer a change or disruption in it -- by site-directed mutagenesis , for example, by deletion of a gene by gene knockout (as can be done in some organisms, such as yeas...

Restriction enzyme

...cal segments that contain a particular nucleotide sequence , and it makes its incisions only within that sequence--known as a " recognition sequence "--always in the same way. Some enzymes make strand incisions immediately opposite one another, p...

Repeated sequence (DNA)

...s, one can distinguish two main types of repeated sequence : Tandem repeats : Satellite DNA , Minisatellite , Microsatellite ; Interspersed repeats : SINE ( S hort IN terspersed E lements), LINE ( L ong IN terspersed E lements)....

Proteomics

...al diagnoal chromatography (COFRADIC). Protein sequence analysis . This is more of a bioinformatic branch, dedicated to searching databases for possible protein or peptide matches, but also functional assignment of domains, prediction of function from sequence, and evolutionary relationships of proteins. ...

Proteolysis

...dues after translation . Removal of the signal sequence of peptides after their transport through a membrane Separation of viral proteins that were translated from a monocistronic mRNA Digestion of proteins from foods as a source of amino acids Conversion of predecessor-proteins (proenzymes...

Proteome

...g in the genome. When the genome is defined by the sequence of nucleotides , the proteome cannot be limited t...by matching the observed peptide masses against a sequence database . Tandem mass spectrometry, on the other hand, can get sequence information from individua...

Protein

... as its native state , which is determined by its sequence of amino acids. Biochemists refer to four distinc...ructure: Primary structure : the amino acid sequence Secondary structure : highly patterned sub-structures— alpha helix and beta sheet &mda...

Promoter

... article In genetics , a promoter is a DNA sequence that enables a gene to be transcribed . The pro...ures. The perfect promoter is called a canonical sequence . Contents showTocToggle("show","hide") 1 Promoter elements 2 Promoter sequences ...

Prion

...fiber to grow. Small differences in the amino acid sequence of prion-forming regions lead to distinct structur...protein molecules that are identical in amino acid sequence to the prion protein can be recruited into the growing fiber. This "specificity" phenomenon may expl...

Primer

...primers is when primer design is based on protein sequence . As several different codons can code for one ...don is used in a particular case. Therefore primer sequence corresponding to the amino acid isoleucine might be "ATH", where A stands for adenine , T for ...

Primary structure

...molecule to obtain either nucleotide or peptide sequence . The primary structure, in other words, is a biopolymer's exact chemical composition and to the sequence in which its subunits are arranged. While the primary structure of a biological polymer to a large ...

Plasmid

...sistance . Every plasmid contains at least one DNA sequence that serves as an origin of replication or ori (a starting point for DNA replication ), which enables the plasmid DNA to be duplicated independently from the chromosomal DNA (Fig. 2). Figure 2 : Schematic drawing of a plasmid with ant...

Photosynthesis

...th processes actually take place through a complex sequence of steps, and are very different in detail. Fallen leaf. Areas where green chlorophyll has been destroyed now appear yellow Plants capture light using the pigment chlorophyll , which gives them their green color . This is contained...

Peroxisome

...h enzyme transferred to a peroxisome has a special sequence at one end of the protein, called a PTS or peroxisomal targeting signal , that allows the protein to be taken into that organelle, where they then function to rid the cell of toxic substances. Peroxisomes also degrade fatty acids and toxic compounds...

Polymerase chain reaction

...primers is when primer design is based on protein sequence . As several different codons can code for one ...don is used in a particular case. Therefore primer sequence corresponding to the amino acid isoleucine might be "ATH", where A stands for adenine , T for ...

Paternity testing

...e it is found in the nucleus . Comparing the DNA sequence of an individual to that of another individual can show if one of them was derived from the other or not. Specific sequences are usually looked at to see if they were copied verbatim from one of the individuals genome to the other. If that was the ca...

Neutral theory of molecular evolution

...neous mutation of a single nucleotide within the sequence of a gene. In single-celled organisms, such an eve... fixed, the effect is to add a substitution to the sequence of the previously fixed allele. In this way, neutral substitutions tend to accumulate, and genomes t...

Magnetic resonance imaging

...which are basic parameters of image acquisition, a sequence will take on the property of T2 weighting. On a T... tends to develop edema, which makes a T2 weighted sequence sensitive for pathology, and generally able to distinguish pathologic tissue from normal tissue. Wi...

Morphogenesis

... and the nanos mRNA. Bicoid binds a specific RNA sequence in the 3' untranslated region of caudal mRNA and blocks translation. Hunchback protein levels in the early embryo are significantly augmented by new hunchback gene transcription and translation of the resulting zygotically produced mRNA. Duri...

Molecular phylogeny

...sms based on the presence or absence, and the DNA sequence , of various genes. See also: phylogeny - molecular evolution - DNA barcode External links A summary of the state of the art at Gary Olsen's Molecular Phylogeny website...

Molecular evolution

...ncing , which allow the determination of the exact sequence of nucleotides or bases in either DNA or RNA. ...esent it is still a long and expensive process to sequence the entire genome of an organism, and this has been done for only a few species. However it is qu...

Molecular biology

...for copying DNA. In brief, PCR allows a single DNA sequence to be copied (millions of times), or altered in predetermined ways. For example, PCR can be used to introduce restriction enzyme sites, or to mutate (change) particular bases of DNA. PCR can also be used to determine whether a particular DNA fragment...

Microsatellite

... A microsatellite is a short, noncoding DNA sequence (a Tandemly Repetitive DNA sequence) that is rep...the same locus. In a microsatellite, the repeated sequence is very simple, consisting of two to four nucleotides, and can be repeated 10 to 100 times. Hence if...

Malaria

...a researchers [2] . It is hoped that the genome sequence of the most deadly agent of malaria, Plasmodium falciparum , which was completed in 2002 , will provide targets for new drugs or vaccines. Efforts to eradicate malaria by attacking mosquitos have been successful in some areas. Malaria was once co...

Long-term potentiation

...). LTP can be induced experimentally by applying a sequence of short, high-frequency stimulations to nerve cell synapses . The phenomenon was discovered in the mammalian hippocampus by Terje Lmo in 1966 and is commonly regarded as the cellular basis of memory . Contents showTocToggle("show","hid...

Lambda phage

... the bacterial genome, called att λ . The sequence of the att site is called att B and consists of the parts B-O-B', whereas thecomplementary sequence in the circular phage genome is called att P and consists of the parts P-O-P'. The integration it...

Lac repressor

...lymerase is like a car . For a specific protein sequence to be made, the car must drive from a specific entrance and get off at the next exit. The repressor in its active form is like a red light at the entrance. The lac repressor works with the cooperation of another regulatory protein that responds ...

Isozyme

...tion ( indel ) events that affect the DNA coding sequence of the gene . As with any other new mutation , there are three things that may happen to a new allozyme: (1) It is most likely that the new allele will be non-functional - in which case it will probably result in low fitness and be removed ...

Ion channel

...hrough electrophysiology , biochemistry , gene sequence comparison and mutagenesis . History The existence of ion channels was hypothesized by the British biophysicists Alan Hodgkin and Andrew Huxley as part of their Nobel Prize -winning theory of the nerve impulse, published in 1952. Channe...

Insulin

...diately shared some of his with Collip. The exact sequence of amino acids comprising the insulin molecule, the so-called primary structure , was determined by British molecular biologist Frederick Sanger . It was the first protein the structure of which was completely determined. For this he was awarded...

Human Genome Project

...dvances in the field of genomics (especially in sequence analysis ), as well as huge advances in computing ... genome upon which gaps can be closed. Each draft sequence has been checked at least four to five times to increase 'depth of coverage' or accuracy. Approximat...

Human

...tegory of great apes . Biologists have compared a sequence of DNA base pairs between humans and chimpanzees, and estimated an overall genetic difference of less than 1 per cent. It has been estimated that the human lineage diverged from that of chimpanzees about five million years ago, and from gorillas ...

Homeobox

A homeobox is a stretch of DNA sequence found in genes involved in the regulation of the development ( morphogenesis ) of animals , fungi and plants . Genes that have a homeobox are called homeobox genes and form the homeobox gene family . A homeobox is about 180 base pairs lon...

Photosynthesis

...th processes actually take place through a complex sequence of steps, and are very different in detail. Fallen leaf. Areas where green chlorophyll has been destroyed now appear yellow Plants capture light using the pigment chlorophyll , which gives them their green color . This is contained...

His-tag

.... It may also be followed by a suitable amino acid sequence that facilitates a removal of the his-tag. Purpose Purification The his-tag can be used in affinity chromatography together with a column that has nickel bound to it. Histidine is a good ligand for nickel so the fusion protein will bi...

Har Gobind Khorana

... synthetic genes just he needs to fax the genetic sequence ....

Glycomics

...s the computational organization and processing of sequence data. External links An article on glycomics appeared New Scientist 26 October , 2002 . It provides a broad insight into some of the challenges and opportunties posed by glycomics, as of 2002....

Genomics

...rising biological discoveries. If a particular DNA sequence or pattern is present among many members of a clade , that sequence is said to have been conserved among the species. Evolutionary conservation of a DNA sequence may im...

Genetics

...dently. Sanger's lab complete the entire genome of sequence of Bacteriophage Φ-X174; . 1983 Kary Ban...romyces cerevisiae is the first eukaryote genome sequence to be released 1998 The first genome sequnce for a multicellular eukaryote, C. elegans is rel...

Genetic recombination

...one by comparing the occurrence of a specific DNA sequence with the appearance of a disease. When a high cor...o is found, it is likely that the appropriate gene sequence is closer. Problems of crossover Crossover recombination can occur between any two double helice...

Genetic fingerprinting

...wo humans will have the vast majority of their DNA sequence in common. Genetic fingerprinting exploits highly variable repeating sequences called microsatellites . Two unrelated humans will be likely to have different numbers of microsatellites at a given locus . By using PCR to detect the number of repea...

Gene therapy

...ted in a bad place — for example within the sequence of an important gene, or within non-coding ( intron ) regions that the cell will never translate to produce protein — then the new gene would not be properly expressed and the cell could be made worse or even cancerous. Scientists are rese...

Genetic code

...the genetic code 4.3 Phase or reading frame of a sequence 5 Origin of the genetic code 6 References...ch will then be folded into a protein . The gene sequence inscribed in DNA, and in RNA, is composed of tri-nucleotide units called codons , each coding for a...

Gene

... the growth of biotechnology and the project to sequence the human genome , the common usage of the word ... of a protein . The genetic code determines the sequence of the amino acids that make up a protein. The coding of a three nucleotide DNA sequence to a spec...

Flagellum

...his. Many components of bacterial flagella share sequence similarity to components of the type III secretion...onents of bacterial and archaeal flagella share no sequence similarity. Instead, some components of archaeal flagella share sequence and morphological similarit...

Expressed sequence tag

An expressed sequence tag or EST is a short sub-sequence of a transcribed protein -coding or non-protein coding DNA sequence . It was originally intended as a way to identify gene transcripts , but has since been instrument...

Ewens's sampling formula

...ber θ , whenever a 1 , ..., a n is a sequence of nonnegative integers such that The phrase "under certain conditions", used above, must of course be made precise. The assumptions are (1) the sample size n is small by comparison to the size of the whole population, and (2) the population ...