Identification and characterization of a locus inhibiting extrachromosomal maintenance of the Streptomyces plasmid SLP1.
We report here the existence and initial characterization of a genetic locus (imp) that inhibits maintenance of SLP1-derived plasmids as extrachromosomal replicons in a manner distinct from normal incompatibility between autonomous SLP1 replicons. The trans-acting imp function has been localized to a 1.8 kb Eco47III restriction fragment present on integrated SLP1 elements. At least part of this DNA segment is absent from SLP1-derived plasmids. DNA sequence analysis of the imp region indicates that it contains three overlapping open reading frames (ORFs) that may constitute a polycistronic operon. The effects of insertions within the imp region indicate that uninterrupted transcription through all three ORFs is necessary for imp activity.
Department of Genetics, Stanford University School of Medicine, CA 94305.
S R
SR
Grant
S C
SC
Lee
K
K
Kendall
S N
SN
Cohen
D000595:Amino Acid Sequence; D001483:Base Sequence; D002872:Chromosome Deletion; D004269:DNA, Bacterial / Q000235:genetics; D004268:DNA-Binding Proteins / Q000235:genetics; D005798:Genes, Bacterial; D008969:Molecular Sequence Data; D010957:Plasmids; D012093:Replicon; D015183:Restriction Mapping; D013302:Streptomyces / Q000235:genetics*
D004269:DNA, Bacterial; D004268:DNA-Binding Proteins