GSBS Student Publications

Title

Temperature sensing in Yersinia pestis: translation of the LcrF activator protein is thermally regulated

GSBS Program

Biochemistry & Molecular Pharmacology

UMMS Affiliation

Graduate School of Biomedical Sciences; Department of Molecular Genetics and Microbiology

Date

12-1-1993

Document Type

Article

Medical Subject Headings

Bacterial Proteins; Base Sequence; *DNA-Binding Proteins; *Gene Expression Regulation, Bacterial; Genes, Bacterial; Immunoblotting; Molecular Sequence Data; Nucleic Acid Conformation; *Protein Biosynthesis; RNA, Bacterial; RNA, Messenger; Restriction Mapping; Temperature; Thermodynamics; *Trans-Activators; Yersinia pestis

Disciplines

Life Sciences | Medicine and Health Sciences

Abstract

The lcrF gene of Yersinia pestis encodes a transcription activator responsible for inducing expression of several virulence-related proteins in response to temperature. The mechanism of this thermoregulation was investigated. An lcrF clone was found to produce much lower levels of LcrF protein at 26 than at 37 degrees C in Y. pestis, although it was transcribed at similar levels at both temperatures. High-level T7 polymerase-directed transcription of the lcrF gene in Escherichia coli also resulted in temperature-dependent production of the LcrF protein. Pulse-chase experiments showed that the LcrF protein was stable at 26 and 37 degrees C, suggesting that translation rate or message degradation is thermally controlled. The lcrF mRNA appears to be highly unstable and could not be reliably detected in Y. pestis. Insertion of the lcrF gene into plasmid pET4a, which produces high levels of plasmid-length RNA, aided detection of lcrF-specific message in E. coli. Comparison of the amount of LcrF protein produced per unit of message at 26 and 37 degrees C indicated that the efficiency of translation of lcrF message increased with temperature. mRNA secondary structure predictions suggest that the lcrF Shine-Dalgarno sequence is sequestered in a stem-loop. A model in which decreased stability of this stem-loop with increasing temperature leads to increased efficiency of translation initiation of lcrF message is presented.

Rights and Permissions

Citation: J Bacteriol. 1993 Dec;175(24):7901-9.

Related Resources

Link to article in PubMed

Journal Title

Journal of bacteriology

PubMed ID

7504666