TY - JOUR
T1 - DNA sequence analysis of the transposon Tn3
T2 - Three genes and three sites involved in transposition of Tn3
AU - Heffron, Fred
AU - McCarthy, Brian J.
AU - Ohtsubo, Hisako
AU - Ohtsubo, Eiichi
N1 - Funding Information:
We would particularly like to thank Hugo Martinez for the computer programming used in the analysis of this DNA sequence, and Ira Herskowitz for his enthusiasm and interest in this project. We would also like to thank Bruce Alberts and Magdelene So for their careful reading of the manuscript. This project was funded in part by grants from the NSF and the NIH, and by a fellowship to F. H. from Smith-Kline.
PY - 1979/12
Y1 - 1979/12
N2 - The complete nucleotide sequence of the transposon Tn3 and of 20 mutations which affect its transposition are reported. The mutations, generated in vitro by random insertion of synthetic restriction sites, proved to contain small duplications or deletions immediately adjacent to the new restriction site. By determining the phenotype and DNA sequence of these mutations we were able to generate an overlapping phenotypic and nucleotide map. This 4957 bp transposon encodes three polypeptides which account for all but 350 bp of its total coding capacity. These proteins are the transposase, a high molecular weight polypeptide (1015 amino acids) encoded by the tnpA gene; the Tn3-specific repressor, a low molecular weight polypeptide (185 amino acids) encoded by the tnpR gene; and the 286 amino acid β-lactamase. The 38 bp inverted repeats flanking Tn3 appear to be absolutely required in cis for Tn3 to transpose. Genetic data suggest that Tn3 contains a third site (Gill et al., 1978), designated IRS (internal resolution site), whose absence results in the insertion of two complete copies of Tn3 as direct repeats into the recipient DNA. We suggest that these direct repeats of complete copies of Tn3 are intermediates in transposition, and that the IRS site is required for recombination and subsequent segregation of the direct repeats to leave a single copy of Tn3 (Gill et al., 1978). A 23 nucleotide sequence within the amino terminus of the transposase which shares strong sequence homology with the inverted repeat may be the internal resolution site.
AB - The complete nucleotide sequence of the transposon Tn3 and of 20 mutations which affect its transposition are reported. The mutations, generated in vitro by random insertion of synthetic restriction sites, proved to contain small duplications or deletions immediately adjacent to the new restriction site. By determining the phenotype and DNA sequence of these mutations we were able to generate an overlapping phenotypic and nucleotide map. This 4957 bp transposon encodes three polypeptides which account for all but 350 bp of its total coding capacity. These proteins are the transposase, a high molecular weight polypeptide (1015 amino acids) encoded by the tnpA gene; the Tn3-specific repressor, a low molecular weight polypeptide (185 amino acids) encoded by the tnpR gene; and the 286 amino acid β-lactamase. The 38 bp inverted repeats flanking Tn3 appear to be absolutely required in cis for Tn3 to transpose. Genetic data suggest that Tn3 contains a third site (Gill et al., 1978), designated IRS (internal resolution site), whose absence results in the insertion of two complete copies of Tn3 as direct repeats into the recipient DNA. We suggest that these direct repeats of complete copies of Tn3 are intermediates in transposition, and that the IRS site is required for recombination and subsequent segregation of the direct repeats to leave a single copy of Tn3 (Gill et al., 1978). A 23 nucleotide sequence within the amino terminus of the transposase which shares strong sequence homology with the inverted repeat may be the internal resolution site.
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U2 - 10.1016/0092-8674(79)90228-9
DO - 10.1016/0092-8674(79)90228-9
M3 - Article
C2 - 391406
AN - SCOPUS:0018630462
SN - 0092-8674
VL - 18
SP - 1153
EP - 1163
JO - Cell
JF - Cell
IS - 4
ER -