This domain is found in two distinct sets of proteins with different functions. Those found in aerobic bacteria bind cellulose (or other carbohydrates); but in anaerobic fungi they are protein binding domains, referred to as dockerin domains or docking domains. They are believed to be responsible for the assembly of a multiprotein cellulase/hemicellulase complex, similar to the cellulosome found in certain anaerobic bacteria.

1: Novel cellulose-binding domains, NodB homologues and conserved modular architecture in xylanases from the aerobic soil bacteria Pseudomonas fluorescens subsp. cellulosa and Cellvibrio mixtus. Millward-Sadler SJ, Davidson K, Hazlewood GP, Black GW, Gilbert HJ, Clarke JH; Biochem J 1995;312:39-48. PMID:7492333

2: Characterization of a cellulosome dockerin domain from the anaerobic fungus Piromyces equi. Raghothama S, Eberhardt RY, Simpson P, Wigelsworth D, White P, Hazlewood GP, Nagy T, Gilbert HJ, Williamson MP; Nat Struct Biol 2001;8:775-778. PMID:11524680

3: A modular cinnamoyl ester hydrolase from the anaerobic fungus Piromyces equi acts synergistically with xylanase and is part of a multiprotein cellulose-binding cellulase-hemicellulase complex. Fillingham IJ, Kroon PA, Williamson G, Gilbert HJ, Hazlewood GP; Biochem J 1999;343:215-224. PMID:10493932

4: Noncatalytic docking domains of cellulosomes of anaerobic fungi. Steenbakkers PJ, Li XL, Ximenes EA, Arts JG, Chen H, Ljungdahl LG, Op Den Camp HJ; J Bacteriol 2001;183:5325-5333. PMID:11514516