The prototypical conjugative plasmid is the F-plasmid, or F-factor.

The F-plasmid is an episome ( a plasmid that can integrate itself into the bacterial chromosome by homologous recombination ) with a length of about 100 kb.

If the F-plasmid that is transferred has previously been integrated into the donor ’ s genome some of the donor ’ s chromosomal DNA may also be transferred with the plasmid DNA.

A bacterial artificial chromosome ( BAC ) is a DNA construct, based on a functional fertility plasmid ( or F-plasmid ), used for transforming and cloning in bacteria, usually E. coli.

There can only be one copy of the F-plasmid in a given bacterium, either free or integrated, and bacteria that possess a copy are called F-positive or F-plus ( denoted F < sup >+</ sup >).

* Superfamily I: UvrD ( E. coli, DNA repair ), Rep ( E. coli, DNA replication ), PcrA ( Staphylococcus aureus, recombination ), Dda ( bacteriophage T4, replication initiation ), RecD ( E. coli, recombinational repair ), TraI ( F-plasmid, conjugative DNA transfer ).

Some strains of bacteria with an integrated F-plasmid can be isolated and grown in pure culture.

Among other genetic information the F-plasmid carries a tra and trb locus, which together are about 33 kb long and consist of about 40 genes.

F1 Filamentous phage infection requires the presence of a pilus so only bacterial hosts containing the F-plasmid or its derivatives can be used to generate phage particles.

* A helper strain, Carrying a conjugative plasmid ( such as the F-plasmid ) that codes for genes required for conjugation and DNA transfer.

Originally synthesized from compounds found in pit viper venom, ACE inhibitors inhibit angiotensin-converting enzyme ( a component of the blood pressure-regulating renin-angiotensin system ), thereby decreasing the tension of blood vessels and blood volume, thus lowering blood pressure.

Angiotensin-converting enzyme inhibitors reduce the activity of the renin-angiotensin-aldosterone system.

Bromine has no essential function in mammals, though it is preferentially used over chloride by one antiparasitic enzyme in the human immune system.

The produced NADH and quinol molecules then feed into the enzyme complexes of the respiratory chain, an electron transport system transferring the electrons ultimately to oxygen and conserving the released energy in the form of a proton gradient over a membrane ( inner mitochondrial membrane in eukaryotes ).

Carbamazepine exhibits autoinduction: it induces the expression of the hepatic microsomal enzyme system CYP3A4, which metabolizes carbamazepine itself.

Part of the renin-angiotensin-aldosterone system, renin is an enzyme involved in the regulation of aldosterone levels.

Nerve agents disrupt the nervous system by inhibiting the function of acetylcholinesterase by forming a covalent bond with the site of the enzyme where acetylcholine normally undergoes hydrolysis ( breaks down ).

Rather than counteracting the initial effects of the nerve agent on the nervous system like atropine, pralidoxime chloride reactivates the poisoned enzyme ( acetylcholinesterase ) by scavenging the phosphoryl group attached on the functional hydroxyl group of the enzyme.

Proton pump inhibitors act by irreversibly blocking the hydrogen / potassium adenosine triphosphatase enzyme system ( the H < sup >+</ sup >/ K < sup >+</ sup > ATPase, or more commonly gastric proton pump ) of the gastric parietal cells.

(" Irreversibility " refers to the effect on a single copy of the enzyme ; the effect on the overall human digestive system is reversible, as the enzymes are naturally destroyed and replaced with new copies.

Upon exposure to gliadin, the enzyme tissue transglutaminase modifies the protein, and the immune system cross-reacts with the bowel tissue, causing an inflammatory reaction.

Reducing enzyme activity can disable a pathogen or correct an incorrectly function system ; as such, many enzyme inhibitors are developed to be used as drugs for the general public.

Lactose intolerant individuals have insufficient levels of lactase, the enzyme that metabolizes lactose into glucose and galactose, in their digestive system.

* 1961 — J. Heinrich Matthaei cracked the first codon of the genetic code ( the codon for the amino acid phenylalanine ) using Grunberg-Manago's 1955 enzyme system for making polynucleotides.

TYR encodes tyrosinase, which is not a component of the immune system, but is an enzyme of the melanocyte that catalyzes melanin biosynthesis, and a major autoantigen in generalized vitiligo.

It is a nerve agent, interfering with normal functioning of the mammalian nervous system by inhibiting the cholinesterase enzyme.

A comparative genomic and phylogenetic analysis of 138 genomes of bacteria, archaea, and eukaryotes found that " the LuxS enzyme required for AI-2 synthesis is widespread in bacteria, while the periplasmic binding protein LuxP is present only in Vibrio strains ," leading to the conclusion that either " other organisms may use components different from the AI-2 signal transduction system of Vibrio strains to sense the signal of AI-2 or they do not have such a quorum sensing system at all.

As a system of enzyme nomenclature, every EC number is associated with a recommended name for the respective enzyme.

To overcome the limitation, a small part of the system is treated quantum-mechanically ( typically active-site of an enzyme ) and the remaining system is treated classically.

However, the system is designed, ingeniously and hopefully, so that no one man could initiate a thermonuclear war.

Presupposed in Plato's system is a doctrine of levels of insight, in which a certain kind of detached understanding is alone capable of penetrating to the most sublime wisdom.

Thus the cocktail party would appear to be the ideal system, but there is one weakness.

For the occasion on which everyone already knows everyone else and the host wishes them to meet one or a few honored newcomers, then the `` open house '' system is advantageous because the honored guests are fixed connective points and the drifting guests make and break connections at the door.

The connective system, or network, is tailored to meet the requirements of the objective, and it is therefore not surprising that a military body acting as a single coordinated unit has a different communication network than a factory, a college, or a rural village.

The problem is rather to find out what is actually happening, and this is especially difficult for the reason that `` we are busily being defended from a knowledge of the present, sometimes by the very agencies -- our educational system, our mass media, our statesmen -- on which we have had to rely most heavily for understanding of ourselves ''.

It is an organized system of these things.

This is necessary for a sounder collective defense system.

It is possible that international organization will ultimately supplant the multi-state system, but its proper function for the immediate future is to reform and supplement that system in order to render pluralism more compatible with an interdependent world.

Air Force life is great, the cadet wrote, `` though the fourth-class system is no fun ''.

An adequate system of VA hospitals is better equipped to care for the veterans than any 50 state hospitals.

The highway system is an agency of government, and when it grinds up 40,000 Americans every year the government is destroying its own taxpayers, which is obviously a silly thing for any government to do.

but the government is left with no reserve granary, under the agricultural system it has ordained.

It is the consequence of the system of ideas that constitutes the frame of our international -- and in some degree our domestic -- policy.

The system is composed of three credit services, Federal Land Banks and National Farm Loan Associations, Federal Intermediate ( short-term ) Credit Banks, and Banks for Cooperatives.