Homologous expansin-like domains in other proteins
In order to find similarities between the expansin family and the GH45 endoglucanase family, a structure-based multiple sequence alignment was performed of the N-terminal expansin domains of five expansins (PDB entries 2bh0, 4jjo, 4fer, 1n10, and 2hcz) and the complete sequences of seven GH45s (PDB entries 1eng, 1hd5, 1oa9, 1wc2, 5h4u, 5kjo, and 5xbu). Five representative sequences of expansin-like proteins were analyzed: swollenin from Trichoderma reesei (NCBI accession AJ245918.1)47, loosenin from Bjerkandera adusta(NCBI accession ADI72050.2)48, EXPN fromEndogone sp. FLAS-F59071 (NCBI accession RUS20349.1)49,50, an expansin-like protein found in nematode Heterodera glycines (NCBI accession ADL29728.1)51, and cerato-platanin fromCeratocystis platani (NCBI accession CAC84090.2)52. The two profile HMMs of the N- and C-terminal expansin domains were used to search within these five expansin-like protein sequences for expansin domains with the filter criteria mentioned above.