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Spermine is a polyamine involved in cellular metabolism that is found in all eukaryotic cells. The precursor for synthesis of spermine is the amino acid ornithine . It is an essential growth factor in some bacteria as well.
Spermine is synthesized from the reaction of spermidine with SAM in the presence of the enzyme spermine synthase. The polyamines undergo rapid interconversion in the polyamine cycle, in which putrescine leads to synthesis of spermidine and spermine, with degradation of these polyamines to form putrescine, which can begin the cycle again. [16]
Spermidine/spermine N(1)-acetyltransferase (SPD/SPM acetyltransferase) is a rate-limiting enzyme in the catabolic pathway of polyamine metabolism. It catalyzes the N(1)-acetylation of spermidine and spermine and, by the successive activity of polyamine oxidase , spermine can be converted to spermidine and spermidine to putrescine . [ 7 ]
Spermine synthase is an enzyme involved in polyamine biosynthesis. It is present in all eukaryotes and plays a role in a variety of biological functions in plants [ 3 ] Its structure consists of two identical monomers of 41 kDa with three domains each, creating a homodimer formed via dimerization .
Putrescine is found in all organisms. [13] Putrescine is widely found in plant tissues, [13] often being the most common polyamine present within the organism. Its role in development is well documented, but recent studies have suggested that putrescine also plays a role in stress responses in plants, both to biotic and abiotic stressors. [14]
Genetic engineering techniques allow the modification of animal and plant genomes. Techniques have been devised to insert, delete, and modify DNA at multiple levels, ranging from a specific base pair in a specific gene to entire genes. There are a number of steps that are followed before a genetically modified organism (GMO) is created.
Microbial genetics is a subject area within microbiology and genetic engineering. Microbial genetics studies microorganisms for different purposes. The microorganisms that are observed are bacteria and archaea. Some fungi and protozoa are also subjects used to study in this field.
Natural genetic engineering (NGE) is a class of process proposed by molecular biologist James A. Shapiro to account for novelty created in the course of biological evolution. Shapiro developed this work in several peer-reviewed publications from 1992 onwards, and later in his 2011 book Evolution: A View from the 21st Century , which has been ...