Abstract

The plasmid pCD1 is required for expression of the low-calcium response (LCR), virulence, and production of V antigen in Yersinia pestis KIM. Five independent mutants constitutive for the LCR at 37 degrees C (Lcrc) were obtained through ethyl methanesulfonate mutagenesis followed by ampicillin enrichment. A sixth, spontaneous mutant was obtained directly through ampicillin enrichment. These mutants failed to grow at 37 degrees C regardless of calcium concentration and produced V antigen constitutively at this temperature. All six mutations were located on pCD1. One mutation was mapped to a 1-kilobase region of lcrA. Based on complementation mapping of this mutation, the lcrA locus was divided into two new loci, lcrD and lcrE. This mutation, lcrE1, did not alter the transcription of other genes in the LCR region and was cis-recessive to lcr mutations. Several lower-molecular-weight outer membrane proteins which were observed in the parent strain grown at 37 degrees C in the presence of 2.5 mM calcium were reduced in quantity or absent from the mutant strain.

Full Text
Paper version not known

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.