W Jiang1, L Fang, M Inouye. 1. Department of Biochemistry, Robert Wood Johnson Medical School, Piscataway, NJ 08854, USA.
Abstract
BACKGROUND: CspA, the major cold-shock protein of Escherichia coli, is transiently induced upon temperature downshift and considered to play an important role in low-temperature adaptation. RESULTS: Overproduction of truncated cspA mRNAs retaining translational ability was found to completely block cell growth at low temperatures. This effect was termed 'low-temperature antibiotic effect of truncated cspA expression (LACE)'. In contrast to the significant reduction of polysomes in normal cells upon cold shock, cells under LACE maintained a high polysome profile, producing only truncated cspA products. Growth inhibition of cells under LACE was suppressed when CspA was overproduced together with the truncated cspA mRNA. CONCLUSION: LACE is caused by the overproduction of a truncated cspA mRNA in the absence of CspA production, which in turn traps all the cellular ribosomes in a non-adaptive form incapable of forming initiation complexes with other cellular mRNAs. LACE may provide a novel approach to the development of a new antibiotic.
BACKGROUND: CspA, the major cold-shock protein of Escherichia coli, is transiently induced upon temperature downshift and considered to play an important role in low-temperature adaptation. RESULTS: Overproduction of truncated cspA mRNAs retaining translational ability was found to completely block cell growth at low temperatures. This effect was termed 'low-temperature antibiotic effect of truncated cspA expression (LACE)'. In contrast to the significant reduction of polysomes in normal cells upon cold shock, cells under LACE maintained a high polysome profile, producing only truncated cspA products. Growth inhibition of cells under LACE was suppressed when CspA was overproduced together with the truncated cspA mRNA. CONCLUSION: LACE is caused by the overproduction of a truncated cspA mRNA in the absence of CspA production, which in turn traps all the cellular ribosomes in a non-adaptive form incapable of forming initiation complexes with other cellular mRNAs. LACE may provide a novel approach to the development of a new antibiotic.