Transfer of the plJ101 plasmid in Streptomyces lividans requires a cis-acting function dispensable for chromosomal gene transfer |
| |
Authors: | Gregg S Pettis Stanley N Cohen |
| |
Institution: | Department of Genetics, Stanford University School of Medicine, Stanford, California 94305, USA.;Department of Medicine, Stanford University School of Medicine, Stanford, California 94305, USA. |
| |
Abstract: | The tra gene of Streptomyces lividans plasmid plJ101 is required for both plasmid DNA transfer and plJ101-induced mobilization of chromosomal genes during mating. We show that a chromosomally inserted copy of tra mediates transfer of chromosomal DNA at high frequency but promotes efficient transfer of plasmids only when they contain a previously unknown locus, here named clt. Insertional mutation or deletion of clt from plJ101 reduced plasmid transfer mediated by either plasmid-borne or chromosomally located tra by at least three orders of magnitude, abolished the transfer-associated pocking phenomenon, and interfered with the ability of tra+ plasmids to promote transfer of chromosomal DNA. Our results indicate that plasmid transfer in S. lividans involves a cis-acting function dispensable for chromosomal gene transfer and imply that either the S. lividans chromosome encodes its own clt-like function or, alternatively, that transfer of plasmid and chromosomal DNA occurs by different mechanisms. |
| |
Keywords: | |
|
|