Site specificity of psoralen-DNA interstrand cross-linking determined by nuclease Bal31 digestion

TY - JOUR

T1 - Site specificity of psoralen-DNA interstrand cross-linking determined by nuclease Bal31 digestion

AU - Zhen, W P

AU - Buchardt, O

AU - Nielsen, Henrik

AU - Nielsen, P E

N1 - Keywords: Base Sequence; DNA; DNA Restriction Enzymes; Endodeoxyribonucleases; Exodeoxyribonucleases; Photochemistry; Plasmids; Psoralens; Trioxsalen

PY - 1986

Y1 - 1986

N2 - A novel method for determination of psoralen photo-cross-linking sites in double-stranded DNA is described, which is based on a pronounced inhibition of Bal31 exonuclease activity by psoralen-DNA interstrand cross-links. The results using a 51 base pair fragment of plasmid pUC19 and a 346 base pair fragment of pBR322 show that 5'-TA sequences are preferred cross-linking sites compared to 3'-TA sequences. They also indicate that sequences flanking the 5'-TA site influence the cross-linking efficiency at the site. The DNA photo-cross-linking by 4,5',8-trimethylpsoralen and 8-methoxypsoralen was analyzed, and these two psoralens showed identical site specificity. The 5'-TA preference is rationalized on the basis of the local DNA structure in terms of the pi-pi electronic interaction between the thymines and the intercalated psoralens, as well as on the base tilt angles of the DNA.

AB - A novel method for determination of psoralen photo-cross-linking sites in double-stranded DNA is described, which is based on a pronounced inhibition of Bal31 exonuclease activity by psoralen-DNA interstrand cross-links. The results using a 51 base pair fragment of plasmid pUC19 and a 346 base pair fragment of pBR322 show that 5'-TA sequences are preferred cross-linking sites compared to 3'-TA sequences. They also indicate that sequences flanking the 5'-TA site influence the cross-linking efficiency at the site. The DNA photo-cross-linking by 4,5',8-trimethylpsoralen and 8-methoxypsoralen was analyzed, and these two psoralens showed identical site specificity. The 5'-TA preference is rationalized on the basis of the local DNA structure in terms of the pi-pi electronic interaction between the thymines and the intercalated psoralens, as well as on the base tilt angles of the DNA.

M3 - Journal article

C2 - 3024713

SN - 0006-2960

VL - 25

SP - 6598

EP - 6603

JO - Biochemistry

JF - Biochemistry

IS - 21

ER -