The Importance of the Small RNA Chaperone Hfq for Growth of EpidemicYersinia pestis, but NotYersinia pseudotuberculosis, with Implications for Plague Biology

Yersinia pestis, the etiologic agent of plague, has only recently evolved from Yersinia pseudotuberculosis. hfq deletion caused severe growth restriction at 37 degrees C in Y. pestis but not in Y. pseudotuberculosis. Strains from all epidemic plague biovars were similarly affected, implicating Hfq, and likely small RNAs (sRNAs), in the unique biology of the plague bacillus.