K u 8 0 ▁heter od imer ▁and ▁DNA - dependent ▁protein ▁kin ase ▁( D NA - PK ), ▁for ▁bringing ▁DNA ▁fragments ▁end ▁together , ▁the ▁Ar tem is ▁nuc lease ▁and ▁pol yn uc le ot ide ▁kin ase ▁ 3 ' ▁ph osph at ase ▁ ▁( PN K P ) ▁, ▁for ▁the ▁end ▁processing , ▁X ▁family ▁DNA ▁polym er ases ▁ ▁( Pol ▁ μ ▁and ▁Pol ▁ λ ) ▁ ▁and ▁terminal ▁de ox yn uc le ot id yl ▁transfer ase ▁ ▁( T d T ) ▁, ▁for ▁DNA ▁synth esis , ▁and ▁X L F / X R CC 4 / L ig IV ▁ ▁complex , ▁for ▁comple ting ▁the ▁repair ▁and ▁joining ▁the ▁ends ▁via ▁a ▁ph osph odi ester ▁bond , ▁are ▁the ▁protein ▁complex es ▁involved ▁in ▁D SB ▁repair ▁process ▁in ▁many ▁higher ▁organ isms . ▁DNA ▁polym er ases ▁ ▁( Pol ▁ μ ▁and ▁Pol ▁ λ ) ▁ ▁and ▁X L F / X R CC 4 / L ig IV ▁complex ▁are ▁shared ▁between ▁two ▁N HE J ▁and ▁M ME J ▁repair ▁mach in ery ▁and ▁have ▁the ▁same ▁responsibility ▁in ▁both ▁repair ▁processes . ▁The ▁first ▁step ▁of ▁M ME J ▁is ▁done ▁by ▁W R N ▁, ▁Ar tem is , ▁DNA - PK ▁, ▁and ▁X R CC 4 ▁protein ▁complex es ▁which ▁process ▁the ▁ends ▁of ▁D SB ▁and ▁m t D NA ▁fragments ▁in ▁addition ▁to ▁align