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Moron (bacteriophage)
A moron, in the context of bacteriophage genetics, is an extra gene in a prophage genome without a function in the phage's lysogenic cycle Lysogeny, or the lysogenic cycle, is one of two cycles of viral reproduction (the lytic cycle being the other). Lysogeny is characterized by integration of the bacteriophage nucleic acid into the host bacterium's genome or formation of a circu .... These genes may code for products beneficial to the phage's bacterial host, as with the example of gp15 of phage HK97 serving as a superinfection exclusion protein. The term moron comes from the notion that the additional genes mean that these bacteriophage genomes have "more on" them. References DNA Bacteriophages {{virus-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bacteriophage
A bacteriophage (), also known informally as a ''phage'' (), is a duplodnaviria virus that infects and replicates within bacteria and archaea. The term was derived from "bacteria" and the Greek φαγεῖν ('), meaning "to devour". Bacteriophages are composed of proteins that encapsulate a DNA or RNA genome, and may have structures that are either simple or elaborate. Their genomes may encode as few as four genes (e.g. MS2) and as many as hundreds of genes. Phages replicate within the bacterium following the injection of their genome into its cytoplasm. Bacteriophages are among the most common and diverse entities in the biosphere. Bacteriophages are ubiquitous viruses, found wherever bacteria exist. It is estimated there are more than 1031 bacteriophages on the planet, more than every other organism on Earth, including bacteria, combined. Viruses are the most abundant biological entity in the water column of the world's oceans, and the second largest component of biom ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Genetics
Genetics is the study of genes, genetic variation, and heredity in organisms.Hartl D, Jones E (2005) It is an important branch in biology because heredity is vital to organisms' evolution. Gregor Mendel, a Moravian Augustinian friar working in the 19th century in Brno, was the first to study genetics scientifically. Mendel studied "trait inheritance", patterns in the way traits are handed down from parents to offspring over time. He observed that organisms (pea plants) inherit traits by way of discrete "units of inheritance". This term, still used today, is a somewhat ambiguous definition of what is referred to as a gene. Trait inheritance and molecular inheritance mechanisms of genes are still primary principles of genetics in the 21st century, but modern genetics has expanded to study the function and behavior of genes. Gene structure and function, variation, and distribution are studied within the context of the cell, the organism (e.g. dominance), and within the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Prophage
A prophage is a bacteriophage (often shortened to "phage") genome that is integrated into the circular bacterial chromosome or exists as an extrachromosomal plasmid within the bacterial cell. Integration of prophages into the bacterial host is the characteristic step of the lysogenic cycle of temperate phages. Prophages remain latent in the genome through multiple cell divisions until activation by an external factor, such as UV light, leading to production of new phage particles that will lyse the cell and spread. As ubiquitous mobile genetic elements, prophages play important roles in bacterial genetics and evolution, such as in the acquisition of virulence factors. Background Prophages are able to do a multitude of things within their respective bacterial strains. Prophages can increase the virulence potential of bacterial strains in both humans and plant pathogens as well as increase the ability of the bacteria to survive in harsh environments. Pathogens have been able to adap ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lysogenic Cycle
Lysogeny, or the lysogenic cycle, is one of two cycles of viral reproduction (the lytic cycle being the other). Lysogeny is characterized by integration of the bacteriophage nucleic acid into the host bacterium's genome or formation of a circular replicon in the bacterial cytoplasm. In this condition the bacterium continues to live and reproduce normally, while the bacteriophage lies in a dormant state in the host cell. The genetic material of the bacteriophage, called a prophage, can be transmitted to daughter cells at each subsequent cell division, and later events (such as UV radiation or the presence of certain chemicals) can release it, causing proliferation of new phages via the lytic cycle. Lysogenic cycles can also occur in eukaryotes, although the method of DNA incorporation is not fully understood. For instance the AIDS viruses can either infect humans (or some other primates) lytically, or lay dormant (lysogenic) as part of the infected cells' genome, keeping the ab ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
HK97
''Escherichia virus HK97'', often shortened to HK97, is a species of virus that infects ''Escherichia coli'' and related bacteria. It is named after Hong Kong (HK), where it was first located. HK97 has a double-stranded DNA genome. Assembly and maturation The major capsid protein of HK97, called gp5, cross-links upon maturation to form a chain-mail like structure. While DNA is being packaged into the capsid, the capsid expands by nearly 5 nm and changes from spherical to icosahedral in shape. The HK97 assembly pathway begins with self-assembly of gp5 into pentamers and hexamers. A protease, called gp4, cleaves gp5 at its N-terminus. Attachment of a portal protein, gp3, coupled with conformational changes leads to the formation of a prohead, or procapsid, which is the precursor to the mature capsid. A scaffolding protein In biology, scaffold proteins are crucial regulators of many key signalling pathways. Although scaffolds are not strictly defined in function, they are k ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
