Regulation of type 1 pili expression as exemplified by Escherichia coli strain M17

Studies of E. coli strain M17 colibacterin and its derivatives showed that fimH gene regulates morphological characteristics of type 1 fimbria and cell piliation on the whole. Gene fimH has a negative effect and decreased the percentage of piliated cells in the population and piliation of individual cells, which does not agree with its role of a positive regulator.