The function of fimbriae in Myxococcus xanthus. I. Purification and properties of M. xanthus fimbriae.

Myxococcus xanthus fimbriae have been purified and characterized as part of a study of the function of fimbriae in this prokaryote. Myxococcus xanthus produced two types of fimbriae, termed flaccid (F) and rigid (R) on the basis of electron microscopy. F and R fimbriae differed slightly in their response to pH and freeze-thaw regimes but were similar in their resistance to hydrolytic enzymes, amino acid composition, molecular weight, carbohydrate content, and antigenic determinants. Although the precise relationship between F and R fimbriae is unknown, the possibility is considered that F fimbriae might represent a "contracted" form of the R type. Studies designed to determine fimbriae function in M. xanthus are described in an accompanying report.