New expression system tightly controlled by zinc availability in Lactococcus lactis.

ABSTRACT: Here we developed the new expression system P(Zn) zitR, based on the regulatory signals (P(Zn) promoter and zitR repressor) of the Lactococcus lactis zit operon, involved in Zn(2+) high-affinity uptake and regulation. A P(Zn) zitR-controlled expression vector was constructed, and expression regulation was studied with two reporter genes, uspnuc and lacLM; these genes encode, respectively, a protein derived from Staphylococcus aureus secreted nuclease and Leuconostoc mesenteroides cytoplasmic beta-galactosidase. Nuclease and beta-galactosidase activities of L. lactis MG1363 cells expressing either uspnuc or lacLM under the control of P(Zn) zitR were evaluated on plates and quantified from liquid cultures as a function of divalent metal ion, particularly Zn(2+), availability in the environme

SUBMITTER: Llull D 

PROVIDER: S-EPMC520854 | biostudies-literature | 2004 Sep

REPOSITORIES: biostudies-literature