Fig. 1

Sequence characteristics of the bHLH domains in different DNA-binding types. Multiple sequence alignments were conducted with the bHLH domains of all candidate proteins and then was conducted with the domains of proteins of a given DNA-binding type. The number in bracket indicates the amount of BnabHLHs in a certain category. Protein secondary structures are illustrated under the sequences. Red asterisks indicate the residues with over 90% similarity; black asterisks indicate residues with over 70% similarity. Black triangles at the top of the sequence indicates the E-box recognition sites; red triangles indicate the G-box recognition sites. The bHLH domains with at least five basic residues but no E-box/G-box binding sites are classified as non-E-box binding genes, otherwise it is a non-DNA binding gene (atypical gene) [6]