▁most ▁distant ▁member ▁with ▁an ▁identity ▁of ▁only ▁~ 3 2 . 3 ▁% ▁when ▁compared ▁to ▁US P 1 5 . ▁An ▁U BL 2 ▁domain ▁insert ion ▁( 2 8 5 aa ) ▁is ▁present ▁within ▁the ▁catal yt ic ▁domain , ▁which ▁en comp ass es ▁am ino ▁ac ids ▁ 3 1 0 ‒ 9 3 1 , ▁and ▁the ▁catal yt ic ▁tri ad ▁consists ▁of ▁a ▁c yst e ine , ▁a ▁hist id ine ▁and ▁an ▁as part ic ▁acid . ▁ ▁Function ▁▁ ▁Prote in ▁u bi quit ination ▁controls ▁many ▁int rac ell ular ▁processes , ▁including ▁cell ▁cycle ▁pro gression , ▁trans cription al ▁activation , ▁and ▁signal ▁trans du ction . ▁This ▁dynamic ▁process , ▁involving ▁u bi quit in ▁conjug ating ▁en zym es ▁and ▁de ub iqu it in ating ▁en zym es , ▁adds ▁and ▁removes ▁u bi quit in . ▁De ub iqu it in ating ▁en zym es ▁are ▁c yst e ine ▁prote ases ▁that ▁specifically ▁cle ave ▁u bi quit in ▁from ▁u bi quit in - con j ug ated ▁protein ▁substr ates . ▁This ▁gene ▁enc odes ▁a ▁de ub iqu it in ating ▁en zym e ▁which ▁lies ▁in ▁a ▁gene ▁cluster ▁on ▁chrom os ome ▁X p 1 1 . 2 3 ▁ ▁Inter actions ▁▁ ▁US P 1 1 ▁has ▁been ▁shown ▁to ▁interact ▁with ▁R AN B P 9 . ▁ ▁Model ▁organ isms ▁▁ ▁Model ▁organ isms ▁have