This Article Full Text Full Text (PDF) Other Versions of this Article: JB.01966-07v1 190/10/3475    most recent Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Copyright Information Books from ASM Press MicrobeWorld Google Scholar Articles by Vrancken, K. Articles by Anné, J. PubMed PubMed Citation Articles by Vrancken, K. Articles by Anné, J.

Characterization of the Streptomyces lividans PspA Response

Laboratory of Bacteriology, Rega Institute for Medical Research, Katholieke Universiteit Leuven, Minderbroedersstraat 10, B-3000 Leuven, Belgium

Received 18 December 2007/ Accepted 26 February 2008

Phage shock protein (Psp) is induced by extracytoplasmic stress that may reduce the energy status of the cell. It is encoded in Escherichia coli by the phage shock protein regulon consisting of pspABCDE and by pspF and pspG. The phage shock protein system is highly conserved among a large number of gram-negative bacteria. However, many bacterial genomes contain only a pspA homologue but no homologues of the other genes of the Psp system. This conservation indicates that PspA alone might play an important role in these bacteria. In Streptomyces lividans, a soil-borne gram-positive bacterium, the phage shock protein system consists only of the pspA gene. In this report, we showed that pspA encodes a 28-kDa protein that is present in both the cytoplasmic and the membrane fractions of the S. lividans mycelium. We demonstrated that the pspA gene is strongly induced under stress conditions that attack membrane integrity and that it is essential for growth and survival under most of these conditions. The data reported here clearly show that PspA plays an important role in S. lividans under stress conditions despite the absence of other psp homologues, suggesting that PspA may be more important in most bacteria than previously thought.

Published ahead of print on 7 March 2008.