ISSN:
1365-2958
Source:
Blackwell Publishing Journal Backfiles 1879-2005
Topics:
Biology
,
Medicine
Notes:
Tn552, one of several closely related β-lactamase-encoding transposons from Staphylococcus aureus, has a novel set of putative transposition functions. Each is homologous with a well-characterized function from a different type of mobile genetic element. Thus, Tn552 encodes: (i) resL-binL, a co-integrate resolution system homologous with those of Tn3 family elements; (ii) p480, a potential transposase significantly homologous with the DNA integrases of eukaryotic retroviruses and retrotransposons; and (iii) p271, a potential ATP-binding protein that shows homology with the B protein of phage Mu. The 3′terminal nucleotides of Tn552 (CA), adjacent to which p480 might cleave, are the same as those of retro-viruses, retrotransposons and phage Mu. The presumptive resolvase (BinL) is very closely related to BinR, which was identified as a DNA invertase and is now shown to resolve an artificial co-integrate in vivo. Furthermore, the structure of the derivative of Tn552 found in the staphylococcal plasmid pl258 can be explained by a BinL (or BinR)-mediated site-specific deletion (‘resolution’) event. Thus, pl258 contains only the right-hand half of Tn552, which encodes the β-lactamase and two regulatory proteins. The latter are homologous with the β-lactamase gene repressor and co-inducer of Bacillus licheniformis. Interestingly, the order of the regulatory genes is reversed in S. aureus compared with Bacillus licheniformis.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1111/j.1365-2958.1990.tb00669.x
Permalink
