Alignment of PopW with pectate lyases of three bacterial and one fungal strain, and HrpW of Erwinia amylovora. The sequences were aligned by the program ClustalX (version 1.83) with default parameters. *, Positions having a single fully conserved residue; :, one of the ‘strong’ groups is fully conserved; ., one of the ‘weaker’ groups is fully conserved. Ba, Bacillus sp. BP‐23; Ea, E. amylovora Ea321; Pel, pectate lyase; Re, Rhizobium etli; Rs, Ralstonia solanacearum UW551; Sd, Saccharophagus degradans 2–40.