DNA sequence analysis of endoglucanase genes fromPseudomonas fluorescens subsp.cellulosa andPseudomonas sp. NCIB 8634

Summary The DNA of two previously isolated recombinant clones, one fromPseudomonas sp. NCIB 8634 (=Cellvibrio mixtus) (pPC71) and another fromPseudomonas fluorescens subsp.cellulosa (pPFC4) that express endoglucanase activity inE. coli was sequenced. Plasmid pPC71 had three open reading frames, two of which include portions of plasmid pBR322. The third open reading frame occurs entirely within thePseudomonas DNA insert and encodes a protein with a molecular mass of 5845 Da. The DNA insert in pPFC4 was found to contain an open reading frame (PFC-ORF) that encodes a protein of 32189 Da. The major endoglucanase produced inE. coli cells carrying pPFC4 is about 30000 Da [26]. It is concluded that PFC-ORF encodes this endoglucanase. Both ribosome and catabolite gene activator protein binding sites lie upstream from the initiating codon of PFC-ORF. An interesting feature of the PFC-ORF protein is the presence of amino acid motifs Val-Ser-Ser-Ser-Ser and Val-Val-Ser-Ser-Ser-Ser-Ser that occur within a 25 amino acid span.