although the unwinding of fully duplex and nicked circular dna molecules reported here occurs at higher helicase ii protein to dna ratios than have been previously used in most studies of this protein in vitro , this activity is likely to be relevant to the function of this protein in vivo since very high levels of helicase ii protein accumulate in e. coli during the sos response to dna damage ( approximately 2-5 x 10 ( 4 ) copies/cell ) .
C0012925
circular dna
C0012854
dna