The nucleotide sequence of an endo-beta-1,4-glucanase gene of Clostridium acetobutylicum contained two putative extended promoter consensus sequences, a Shine-Dalgarno sequence and a TTG initiation codon. The nucleotide sequence of the gene coding for the C-terminal region of this enzyme was not required for activity. Extensive homology in the nucleotide and amino acid sequences of the endoglucanase genes from C. acetobutylicum and Bacillus spp. was demonstrated.