PMID-sentid	Pub_year	Sent_text		comp_official_name	comp_offsetprotein_name	organism	prot_offset
17643376-2	2007	We previously studied histone H2B ubiquitylation on lysine 123 and subsequent deubiquitylation by SAGA-associated Ubp8.	Lysine	52-58	H2B clustered histone 21	Homo sapiens	30-33