Title: <i>Escherichia coli</i>pH 2.5 acid phosphatase and β-lactamase TEM2 are secreted into the medium by<i>Myxococcus xanthus</i>
Abstract: The genes appA, coding for the periplasmic pH 2.5 acid phosphatase of Escherichia coli, and bla, borne by Tn1 coding for TEM2 β-lactamase, another periplasmic enzyme in Gram-negative bacteria, have been transferred and expressed in Myxococcus xanthus. The specified enzymes could be recovered from both cells and extracellular fluid. The pH 2.5 acid phosphatase was expressed in the same way as genuine extracellular proteins in Myxococcus. This activity was recovered throughout exponential growth and was modulated by mutations that affected he total amount of extracellular proteins. A possible mechanism for protein secretion in Myxococcus is discussed in view of these results.