Additional factors for anaerobic survival
Investigation of pyruvate fermentation led to the identification
of UspK (PA3309) which belongs to the universal stress protein
group (Schreiber et al., 2006). Universal stress proteins (Usp) are
found in numerous organisms from all kingdoms of life, but their
function is unknown, and they also share no homology to other
stress proteins as, e.g., heat shock proteins (Kvint et al., 2003;
O’Toole and Williams, 2003). Mutant studies as well as biochemical
data from investigation of Usps in E. coli indicate that these proteins
increase endurance and survival during a variety of different stress
conditions