TABLE 2.

Additional mutations of MotA residues Pro 173 and Pro 222^a

Mutation	Swarming rateb	Dominancec
Proline 173
P173C	0.1	0.8
P173H	0.0	0.4
P173K	0.0	0.6
P173Q	0.0	0.5
Proline 222
P222C	0.0	0.4
P222F	0.0	0.4
P222H	0.0	0.3
P222I	0.0	0.2
P222K	0.0	0.2
P222M	0.0	0.3

^aOther mutations of Pro 173 and Pro 222 were reported previously (40). These include the other 15 possible replacements of Pro 173 and mutations of Pro 222 to Arg, Gln, Glu, Gly, Leu, Ser, Thr, Trp, Tyr, and Val. Like the Pro 222 mutations reported here, all of the previously reported Pro 222 replacements abolished swarming. Among the 15 Pro 173 replacements reported before, six supported partial function. These were mutations to Asn, Leu, Met, Ser, Thr, and Val. 

^bSwarming rates of the motA mutant strain MS5037 transformed with derivatives of plasmid pAlter-1 (see Materials and Methods) encoding the motA mutations. This plasmid expresses MotA at levels comparable to those of the wild-type chromosomally encoded protein. Rates are relative to a control expressing wild-type motA from the same vector. 

^cSwarming rates of wild-type cells expressing the mutant MotA proteins from derivatives of pAlter-1, relative to those of a wild-type control expressing wild-type MotA from the plasmid.