Tn7 transposition: two transposition pathways directed by five Tn7-encoded genes.
نویسندگان
چکیده
The bacterial transposon Tn7 is capable of high-frequency transposition to a specific site in the Escherichia coli chromosome, attTn7, and of low-frequency transposition to sites other than attTn7. Using an in vitro insertional mutagenesis procedure, we have identified and characterized five tns (Tn seven) genes that are essential for Tn7 transposition. Three of these genes, tnsA, tnsB, and tnsC, are required, but are not sufficient, for all Tn7 transposition events. In addition, tnsD is specifically required for transposition to attTn7, whereas tnsE is specifically required for transposition to other sites. Thus, Tn7 is an elaborate transposon that encodes two distinct but overlapping transposition pathways.
منابع مشابه
Conjugating plasmids are preferred targets for Tn7.
Most transposons display target site selectivity, inserting preferentially into sites that contain particular features. The bacterial transposon Tn7 possesses the unusual ability to recognize two different classes of target sites. Tn7 inserts into these classes of target sites through two transposition pathways mediated by different combinations of the five Tn7-encoded transposition proteins. I...
متن کاملAvoiding self: two Tn7-encoded proteins mediate target immunity in Tn7 transposition.
The bacterial transposon Tn7 exhibits target immunity, a process that prevents Tn7 from transposing into target DNAs that already contain a copy of the transposon. This work investigates the mechanism of target immunity in vitro. We demonstrate that two Tn7-encoded proteins_TnsB, which binds specifically to the ends of Tn7, and TnsC, the ATP-dependent DNA binding protein_act as a molecular swit...
متن کاملHost proteins can stimulate Tn7 transposition: a novel role for the ribosomal protein L29 and the acyl carrier protein.
The bacterial transposon Tn7 is distinguished by its ability to insert at a high frequency into a specific site in the Escherichia coli chromosome called attTn7. Tn7 insertion into attTn7 requires four Tn7-encoded transposition proteins: TnsA, TnsB, TnsC and TnsD. The selection of attTn7 is determined by TnsD, a sequence-specific DNA-binding protein. TnsD binds attTn7 and interacts with TnsABC,...
متن کاملPurification of TnsB, a transposition protein that binds to the ends of Tn7.
We have purified TnsB, a transposition protein encoded by the bacterial transposon Tn7. The purification procedure involves three chromatographic steps (DNA-cellulose, norleucine-Sepharose, and phosphocellulose) and yields milligram quantities of highly purified protein. The apparent molecular mass of denatured TnsB protein is approximately 85 kDa. Gel filtration chromatography and sucrose grad...
متن کاملTransposon Tn7. cis-Acting sequences in transposition and transposition immunity.
We have identified and characterized the cis-acting sequences at the termini of the bacterial transposon Tn7 that are necessary for its transposition. Tn7 participates in two kinds of transposition event: high-frequency transposition to a specific target site (attTn7) and low-frequency transposition to apparently random target sites. Our analyses suggest that the same sequences at the Tn7 ends ...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
عنوان ژورنال:
- Genes & development
دوره 2 2 شماره
صفحات -
تاریخ انتشار 1988