Structural features of the Clostridium thermocellum cellulase SS gene

The Clostridium thermocellum cellulase SS is a subunit of the extracellular cellulase complex (cellulosome). It has previously been shown that SS, hydrolyzes crystalline cellulose synergistically with another subunit, SL. To study this synergism further, the authors cloned the gene coding for SS (celS) and compared its sequence to other known cel genes. The celS, although unique in its DNA sequence, has many structural features similar to those found in other cel genes. These features include a ribosome biding site, signal peptide sequence, the existence of a conserved reiterated amino acid sequence, and a palindromic structure downstream from its open reading frame.