Beta- N-acetylglucosaminidase [Carbohydrate transport and metabolism].

Bacterial SH3 domain.

Cadherin-like beta sandwich domain. This domain is found in several bacterial, metazoan and chlorophyte algal proteins. A profile-profile comparison recovered the cadherin domain and a comparison of the predicted structure of this domain with the crystal structure of the cadherin showed a congruent seven stranded secondary structure. The domain is widespread in bacteria and seen in the firmicutes, actinobacteria, certain proteobacteria, bacteroides and chlamydiae with an expansion in Clostridium. In contrast, it is limited in its distribution in eukaryotes suggesting that it was derived through lateral transfer from bacteria. In prokaryotes, this domain is widely fused to other domains such as FNIII (Fibronectin Type III), TIG, SLH (S-layer homology), discoidin, cell-wall-binding repeat domain and alpha-amylase-like glycohydrolases. These associations are suggestive of a carbohydrate-binding function for this cadherin-like domain. In animal proteins it is associated with an ATP-grasp domain.