4. Conclusions
Bioinformatics analysis reveals the sequence-based features of putative GH57GBE sequences, that are two GH57GBE-specific sequence logos, variations in flexible loop and presence/absence of two β-sheets, were noted in 2,497 sequences, with a majority of them (92%) having no flexible loop and absence of two β-sheets; Biochemical data verified that putative GH57GBE sequences can be defined by the former feature and true GH57GBEs can be designated by the latter two structural features which were assigned as optimal flexible loop and presence of two β-sheets. These results guide us to further investigate GH57GBEs or –like sequences in an explicit direction.