New endo-beta-1,4-glucanases from the parabasalian symbionts, Pseudotrichonympha grassii and Holomastigotoides mirabile of Coptotermes termites.

Abstract. An endo-beta-1,4-glucanase (EG) was purified from the hindgut of an Australian mound-building termite, Coptotermes lacteus. The hindgut extract had a peak separate from those for extracts obtained from the salivary glands and the midgut based on sephacryl S-200 gel chromatography, and also demonstrated an origin different from the endogenous EGs of the termite itself. The recovery was further purified by SDS-PAGE, and its N-terminal amino acid sequence analyzed. This showed high homology to EGs from glycoside hydrolase family (GHF) 7. PCR-based cloning methods were applied to the hindgut contents of C. lacteus and individual protozoan symbionts from C formosanus. cDNAs encoding putative EGs homologous to GHF7 members were then identified. The functionality of one of the putative proteins was confirmed by its expression in Escherichia coli.