THE AMINO TERMINUS OF THE TYPE IV PILIN BUNDLIN IS MODIFIED BY N-METHYLATION

Type IV pilin proteins are modified from precursor forms by prepilin peptidase enzymes. In several cases the mature pilin has been shown to contain an N-methylated amino terminal residue. Here the isolation of bundle-forming pili from enteropathogenic Escherichia coli is described and the amino-terminal residue is found to be consistent with N-methylleucine, resolving a previous discrepancy in the literature.