The modular cellulase CelZ of the thermophilic bacterium Clostridium stercorarium contains a thermostabilizing domain.
The non-catalytic region of the Clostridium stercorarium cellulase CelZ (Avicelase I) comprises two protein segments (C and C') grouped into different subfamilies of cellulose-binding domain (CBD) family III. The C-terminally located family IIIb domain C was identified as a true cellulose-binding domain responsible for anchoring the CelZ enzyme to cellulose. The family IIIc domain C' immediately adjacent to the catalytic domain was unable to mediate binding to cellulose. A deletion study revealed a lack of independence of this pair of domains: almost the entire C' domain was required to maintain the catalytic activity and the thermostability of the enzyme.
Institut für Mikrobiologie, Technische Universität München, Germany.
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Riedel
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Ritter
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Bauer
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Bronnenmeier
D001665:Binding Sites; D002384:Catalysis; D002480:Cellulase / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D002482:Cellulose / Q000378:metabolism; D043366:Cellulose 1,4-beta-Cellobiosidase; D003013:Clostridium / Q000201:enzymology* / Q000235:genetics; D004795:Enzyme Stability; D005798:Genes, Bacterial; D006358:Hot Temperature; D010957:Plasmids / Q000235:genetics; D011487:Protein Conformation; D017384:Sequence Deletion; D013329:Structure-Activity Relationship
D002482:Cellulose; D002480:Cellulase; D043366:Cellulose 1,4-beta-Cellobiosidase