Isolation and characterization of novel plasmid-encoded umuC mutants

Isolation and characterization of novel plasmid-encoded umuC mutants.

Most inducible mutagenesis in Escherichia coli is dependent upon the activity of the UmuDC proteins. The role of UmuC in this process is poorly understood, possibly because of the limited number of genetically characterized umuC mutants. To better understand the function of the UmuC protein in mutagenic DNA repair, we have isolated several novel plasmid-encoded umuC mutants. A multicopy plasmid...

Isolation and Characterization of Saccharomyces cerevisiae Mutants

Aculeacin A is a lipopeptide that inhibits ,B-glucan synthesis in yeasts. A number of Saccharomyces cerevisiae mutants resistant to this antibiotic were isolated, and four loci (ACRI, ACR2, ACR3, and ACR4) whose products are involved in the sensitivity to aculeacin A of yeast ceils were defined. Mutants containing mutations in the four loci were also resistant to echinocandin B, another member ...

Cloning and characterization of a novel, plasmid-encoded trimethoprim-resistant dihydrofolate reductase from Staphylococcus haemolyticus MUR313.

In recent years resistance to the antibacterial agent trimethoprim (Tmp) has become more widespread, and several trimethoprim-resistant (Tmpr) dihydrofolate reductases (DHFRs) have been described from gram-negative bacteria. In staphylococci, only one Tmpr DHFR has been described, the type S1 DHFR, which is encoded by the dfrA gene found on transposon Tn4003. In order to investigate the coincid...

Characterization of a Novel Partition System Encoded by the and Genes from the Streptococcal Plasmid pSM19035

High segregational stability of the streptococcal plasmid pSM19035 is achieved by the concerted action of systems involved in plasmid copy number control, multimer resolution, and postsegregational killing. In this study, we demonstrate the role of two genes, and , in plasmid stabilization by a partition mechanism. We show that these two genes can stabilize the native pSM19035 replicon as well ...

Plasmid isolation. Fatemeh Mehrpooyan*