Summary of mutations in MglA and their corresponding phenotypes with regard to M. xanthus motility. Sixteen residues on WT MglA were targeted to make 18 point mutants. Nine mutants made MglA protein and were divided into groups based on phenotype and distribution of MglA (mot- (nonmotile), swm- (do not swarm), dev- (do not develop) and spo- (do not sporulate). Mutants that showed near WT phenotypes were scored as mot+ dev+. Those that showed only partial restoration of a characteristic were scored as (+). Those showed restoration of motility are called class I mutants, those that did not show a full restoration of motility are class II mutants. A subset of class II mutants which include the surface mutants D52A and T54A fail to localize correctly as identified using immunofluorescence microscopy. The remaining class II mutants localize correctly, but do not restore motility. The remaining nine point mutants failed to accumulate detectable amounts of MglA and are classified as class III mutants, which are mot- and dev-. Localization patterns are shown for each motility phenotype and mutant class.