Design of a fungal cellulose-binding domain for PCR amplification and expression in E. coli

A new fungal cellulose binding domain (CBD) from Stachybotris sp. has been cloned. Multiple sequence alignment of the CBD from 34 fungi shows highest sequence identity at the ends of the domains. The two primers from these regions were amplified by PCR giving a 120-bp product. Two of these, from Trichoderma sp. and Stachybotris sp. were subsequently cloned, sequenced and confirmed to be of the CBD family. The CBD from Stachybotris sp. was expressed in E. coli fused to g3p of the M13 phage and with a c-myc tag. The secreted fusion protein adsorbed on acid-swollen cellulose thereby confirming its functionality.