Staphylococcal enterotoxin A gene is associated with a variable genetic element.

M J Betley; S Löfdahl; B N Kreiswirth; M S Bergdoll; R P Novick

doi:10.1073/pnas.81.16.5179

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Staphylococcal enterotoxin A gene is associated with a variable genetic element.

M J Betley·S Löfdahl·B N Kreiswirth·M S Bergdoll·R P Novick

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Abstract

The genetic determinant of Staphylococcus aureus enterotoxin A (SEA) has been cloned in pBR322 in Escherichia coli and found to be expressed and secreted into the periplasmic space in that organism. The SEA gene (entA) is within a 2.5-kilobase-pair HindIII fragment that is part of a discrete genetic element 8-12 kilobase pairs in length. This entA element has a standard chromosomal location [between the purine (pur) and isoleucine-valine (ilv) markers] in most S. aureus strains. In some strains it is unlinked to pur-ilv. However, its internal structure is conserved at different locations. Some naturally occurring SEA-nonproducer (EntA-) strains lack the entire entA element, and one instance of its spontaneous loss is reported. Other naturally occurring strains have EntA- structural variants of the element at the same pur-ilv location at which the intact element is most commonly found. Some of these strains are EntA-, others are EntA+; the latter have a second, unlinked copy of the element containing their functional entA gene. These results suggest that entA is associated with a structurally unstable, possibly mobile, discrete genetic element.

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DNA Restriction Enzymes Enterotoxins Escherichia coli Genes Genes, Bacterial Genotype Nucleic Acid Hybridization Plasmids Species Specificity Staphylococcus aureus Comparative Study Journal Article Research Support, Non-U.S. Gov't Research Support, U.S. Gov't, Non-P.H.S.

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M J Betley, S Löfdahl, B N Kreiswirth, M S Bergdoll, R P Novick. 1984. Staphylococcal enterotoxin A gene is associated with a variable genetic element.. https://doi.org/10.1073/pnas.81.16.5179

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