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The chromosomal integration site for the Streptomyces plasmid SLP1 is a functional tRNA Tyr gene essential for cell viability
Author(s) -
Vögtli Martin,
Cohen Stanley N.
Publication year - 1992
Publication title -
molecular microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.857
H-Index - 247
eISSN - 1365-2958
pISSN - 0950-382X
DOI - 10.1111/j.1365-2958.1992.tb01762.x
Subject(s) - biology , streptomyces coelicolor , genetics , plasmid , streptomyces , gene , chromosomal region , locus (genetics) , mutant , bacteria
Summary The genetic element SLP1 exists in nature as a single DNA segment integrated into the genome of Streptomyces coelicolor. Upon mating with Streptomyces lividans , a closely related species, SLP1 undergoes precise excision from its chromosomal site and is transferred into the recipient where it integrates chromosomally. Previous work has shown that integration and excision involve site‐specific recombination between a chromosomal site, attB , and a virtually identical sequence, attP , on SLP1. We demonstrate here by means of gene replacement that a tRNA Tvr sequence that overlaps part of the attB site of S. lividans is both biologically functional and essential for cell viability. The requirement for this tRNA gene has been used to stabilize the inheritance of a segrationally unstable plasmid in cells lacking a chromosomal attB site. The evolution of an essential DNA locus as an attachment site for a chromosomally integrating genetic element represents a novel mechanism of biological adaptation.