MUTATIONS IN 2 NEW LOCI THAT IMPAIR BOTH EXTRACELLULAR PROTEIN-PRODUCTION AND DEVELOPMENT IN MYXOCOCCUS-XANTHUS

Two transposon insertion mutants of Myxococcus xanthus altered in the secretion of protein as determined by the hydrolytic activities of sev eral enzymes during vegetative growth were also unable to complete fru iting body formation and were severely impaired in sporulation. The in sertions were located in the same part of the M.. xanthus chromosome b ut were unlinked by transduction and therefore define two distinct loc i, called excA and ercB. Since both Exc+/- mutants were able to rescue development of an asgB mutation, they do not belong to the Asg- group , despite of the fact that asg mutants are also Exc+/-. Our results su stain the hypothesis of a possible relationship between protein secret ion during vegetative growth and development or sporulation.