A non-abelian 2-group whose endomorphisms generate a ring, and other examples of E-groups
Groups for which the distributively generated near-ring generated by the endomorphisms is in fact a ring are known as E-groups and are discussed in (3). R. Faudree in (1) has given the only published examples of non-abelian E-groups by presenting defining relations for a family of p–groups. However, as shown in (3), Faudree's group does not have the desired property when p = 2.
Endomorphism Near-Rings Through the Ages
For some 35 years problems concerning morphism near-rings have been studied. In this paper, three areas of such investigation are surveyed, and significant unsolved or partially solved problems from each area are discussed. The first area is centered about the question as to whether an arbitrary distributively generated near-ring can be embedded in some E(G). The motivating problem of the second area is the determination of the groups G such that E(G) is a ring. The third area is typified by the problem of finding the groups G such that I(G) = E(G). The first two areas seem to lie fallow at the moment; the third area is one of current investigation.
Characterization and gene cloning of a maltotriose-forming exo-amylase from Kitasatospora sp. MK-1785
A maltotriose-forming amylase (G3Amy) from Kitasatospora sp. MK-1785 was successfully isolated from a soil sample by inhibiting typical extracellular α-amylases using a proteinaceous α-amylase inhibitor. G3Amy was purified from the MK-1785 culture supernatant and characterized. G3Amy produced maltotriose as the principal product from starch and was categorized as an exo-α-amylase. G3Amy could also transfer maltotriose to phenolic and alcoholic compounds. Therefore, G3Amy can be useful for not only maltotriose manufacture but also maltooligosaccharide-glycoside synthesis. Further, the G3Amy gene was cloned and expressed in Escherichia coli cells. Analysis of its deduced amino acid sequence revealed that G3Amy consisted of an N-terminal GH13 catalytic domain and two C-terminal repeat starch-binding domains belonging to CBM20. It is suggested that natural G3Amy was subjected to proteolysis at N-terminal region of the anterior CBM20 in the C-terminal region. As with natural G3Amy, recombinant G3Amy could produce and transfer maltotriose from starch.