Alternative folding to a monomer or homopolymer is a common feature of the type 1 pilus subunit FimA from enteroinvasive bacteria — Alternative folding possibilities of the pilus subunit FimA — Alternative folding to a monomer or homopolymer is a common feature of the type 1 pilus subunit FimA from enteroinvasive bacteria — Alternative folding possibilities of the pilus subunit FimA