title: Myxococcus xanthus protein C is a major spore surface protein.
abstract: Fruiting body formation in Myxococcus xanthus involves the aggregation of cells to form mounds and the differentiation of rod-shaped cells into spherical myxospores. The surface of the myxospore is composed of several sodium dodecyl sulfate (SDS)-soluble proteins, the best characterized of which is protein S (Mr, 19,000). We have identified a new major spore surface protein called protein C (Mr, 30,000). Protein C is not present in extracts of vegetative cells but appears in extracts of developing cells by 6 h. Protein C, like protein S, is produced during starvation in liquid medium but is not made during glycerol-induced sporulation. Its synthesis is blocked in certain developmental mutants but not others. When examined by SDS-polyacrylamide gel electrophoresis, two forms of protein C are observed. Protein C is quantitatively released from spores by treatment with 0.1 N NaOH or by boiling in 1% SDS. It is slowly washed from the spore surface in water but is stabilized by the presence of magnesium. Protein C binds to the surface of spores depleted of protein C and protein S. Protein C is a useful new marker for development in M. xanthus because it is developmentally regulated, spore associated, abundant, and easily purified.
authors.affiliation: Department of Molecular and Cell Biology, University of California, Berkeley 94720.
authors.forename: W R
authors.initials: WR
authors.lastname: McCleary
authors.forename: B
authors.initials: B
authors.lastname: Esmon
authors.forename: D R
authors.initials: DR
authors.lastname: Zusman
mesh_terms: D000954:Antigens, Surface / Q000032:analysis*; D001426:Bacterial Proteins / Q000032:analysis* / Q000096:biosynthesis / Q000276:immunology; D002454:Cell Differentiation; D015180:Electrophoresis, Gel, Two-Dimensional; D005990:Glycerol / Q000494:pharmacology; D006090:Gram-Negative Bacteria / Q000032:analysis / Q000502:physiology; D008970:Molecular Weight; D009231:Myxococcales / Q000032:analysis / Q000502:physiology*; D013171:Spores, Bacterial / Q000032:analysis*
chemical_list: D000954:Antigens, Surface; D001426:Bacterial Proteins; D005990:Glycerol