, 1993; Soto et al., 1998). Here we show that when nine alternating hydrophobic/hydrophilic residues are removed from the carboxy-terminal end of PsaA, the PsaA synthesis is drastically affected even with the coexpression of the chaperone and usher protein PsaB/PsaC. Although
additional experiments are required to validate this result, this suggests that this PsaA region is essential for its biogenesis. The coexpression of PsaA with the PsaB chaperone protein allowed the detection of PsaA in the cytoplasm, periplasm and membrane PLX4032 in vitro fraction. The role of PsaB in the cytoplasm possibly to avoid the degradation of PsaA and the cytoplasmic interactions between PsaA/PsaB still needs to be established. In contrast, the coexpression of PsaA with only PsaC resulted in a lack of detection of PsaA, confirming that the interaction of PsaABC proteins is essential in the secretion process of PsaA. These results will help to provide new design strategies for delivery of PsaA in RASV strains using their own secretion pathway. Combined with a new more efficient SPase-I cleavage site, these strategies should aid in improving RASV for the effective delivery Y. pestis antigens. We are thankful to Dr J.D. Fetherston (University of Kentucky, Lexington) who generously provided the Y. pestis P325 strain. We
also thank Dr Clara Espitia (UNAM, Mexico) for her critical reading of the manuscript and Dr David S. Reiner (Burnham Institute for Medical Research) and Isabel signaling pathway Perez Montfort (UNAM, Mexico) for correction of the English version of this manuscript. This research was supported by the National Institutes of Health, grant AI057885. Table S1. Oligonucleotides used in this work. Please note: Wiley-Blackwell is not responsible for for the content or functionality of any supporting materials supplied by the authors. Any queries (other than missing material) should be directed to the corresponding author for the article. “
“The effects of overexpression of the apurinic/apyrimidinic
DNA endonuclease Nfo on wet and dry heat and UV-C (254 nm) resistance of Bacillus subtilis spores with or without α/β-type small, acid-soluble spore proteins (SASP) were determined. Results revealed that overexpression of Nfo ≥50-fold in spores increased the wet heat resistance of exoA nfo B. subtilis spores (termed α−β−) that lack most α/β-type SASP, but had no effect on these spores’ UV-C resistance. Nfo overexpression also increased these spores’ dry heat resistance, and to levels slightly greater than that of wild-type spores. These results are consistent: (1) with wet and dry heat (but not UV-C) generating abasic sites in α−β− spore DNA; (2) with dry heat generating some of these lesions in spores that retain α/β-type SASP; and (3) indicate that Nfo can repair these abasic lesions following spore germination.