Fig. 1

Bioinformatics analysis of DUF231-containing proteins in Arabidopsis and Populus. a Maximum likelihood phylogenetic tree of Arabidopsis and Populus DUF231-containing proteins. The numbers at the branches denote bootstrap confidence values. Note that 48 of the 52 PtDUF231 proteins share each node with Arabidopsis DUF231 proteins (red arrows mark four PtDUF231 proteins that are not shared a node with Arabidopsis DUF231 proteins). The location of PtDUF231A (Potri.009G072800) is indicated in the PMR5 clade by a blue asterisk. b Amino acid sequence alignment by MUSCLE. Note that PtDUF231A (Potri.009G072800) shows 52.5% amino acid identity with Arabidopsis PMR5 and 55.9% identity with TBL45. The closest paralog for PtDUF231A is PtDUF231B (Potri.001G278300) with 89.4% identity at the amino acid level. Blue lined brackets shown in the left illustrate the phylogenic tree as shown in a. Red horizontal box marks the amino acid alignment of PtDUF231A-containing node. Blue arrow points Potri.001G010900 which contains both TBL and DUF231 domains but without N-terminal sequences. Three well-conserved protein domains including TM, TBL, and DUF231 are indicated in boxes. c Diagram of amino acid sequence alignment of TBL and DUF231 domains among PtDUF231A, its Populus paralog, its Arabidopsis ortholog (PMR5) and TBL45, in the node shown in b. Consensus sequence was defined by 50% threshold of amino acid sequence identity. The upper panel shows sequence identity using different colors (yellow: over 50%, red: 100% conserved). All conserved regions including GDSL are indicated by the black box. Note that the TBL and DUF231 domains are highly conserved in the PdDUF231A protein