Based on the structural analysis, until now all the PAR-binding modules have been reported to recognize only one or two ADPr units15,35,36,37,38,39,40,41.
Besides macrodomains, another three evolutionary conserved PAR-binding modules have been described: PBM (PAR-binding motif) [49], PAR-binding zinc finger (PBZ) [50] and WWE domains [51].
Novel carbohydrate-binding module have been identified in a ruminal metagenome [ 32].
An ATPS study on the affinity separation in partitioning Cellulomonas fimi β-mannanase (EC 3.2.1.78) containing a mannan-binding module has been investigated by Antov et al. (2006) using polysaccharides from galactomannan and hydroxypropyl starch.
The CBM6 modules have been demonstrated to have binding specificities towards a number of substrates, including both branched and debranched xylan, β-1,4-glucan (cellulose), and agarose [ 48].
The main binding modules that have been identified in mammals are the C1, C2, FERM, PX, and PH domains.
LysMs are N-acetyl D-glucosamine (chitin) binding modules that have been found in mammalian and plant pathogenic fungi as well as in saprophytes [ 50].
Monoclonal antibodies and naturally existing carbohydrate binding modules (CBMs) have been used in the past to assess the presence of certain carbohydrates in plant tissues.
