4jk0 is a 2 chain structure with sequence from Tbsv. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance.
[P19_TBSVK] Viral suppressor of RNA silencing which binds specifically to silencing RNAs (siRNAs). Acts as a molecular caliper to specifically select siRNAs based on the length of the duplex region of the RNA (By similarity).