Fig. 1

Phylogenetic analysis of microbial expansin sequences. a Phylogenetic tree constructed from 1575 sequences related to Bacillus subtilis, EXLX1. The major cluster of expansin-like proteins from bacterial and Phytophthora organisms and query expansin-like sequence from B. subtilis EXLX1 are highlighted on the outside of the tree. Bootstrap values were calculated with 900 iterations. b Microbial phyla encoding expansin-like sequences include bacterial plant pathogens (> 97%) and Eukaryotes (< 3%). c The distribution of dominant bacterial genera (> 99%) versus Phytophthora (< 1%) that encode expansin-like sequences. d The modular organization found among retrieved expansin-like sequences. The gray bar indicates the linker region among Carbohydrate-Binding Module 2 (CBM2) and the D1 or D2 domain. GH5 indicates Glycoside Hydrolase family 5