25052
The structure of the complex between soluble mature RgpB , consisting of a catalytic domain and an immunoglobulin - superfamily domain , and its 205 - residue N - terminal pro - domain , the largest structurally characterized to date for a cysteine peptidase , reveals a novel fold for the pro - domain that is distantly related to sugar - binding lectins .
 N, cysteine, sugar
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: Chemical 
Text: {0} 
Answer:
 N, cysteine, sugar