Interaction of Nucleotide Excision Repair Factors RPA and XPA with DNA Containing Bulky Photoreactive Groups Imitating Damages

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E. A. Maltseva^1,2, N. I. Rechkunova¹, I. O. Petruseva¹, V. N. Silnikov¹, W. Vermeulen³, and O. I. Lavrik^1*

¹Institute of Chemical Biology and Fundamental Medicine, Siberian Branch of the Russian Academy of Sciences, pr. Akademika Lavrent'eva 8, 630090 Novosibirsk, Russia; fax: (383) 333-3677; E-mail: lavrik@niboch.nsc.ru

²Novosibirsk State University, ul. Pirogova 2, 630090 Novosibirsk, Russia

³Center for Biomedical Genetics, Department of Cell Biology and Genetics, Erasmus Medical Center, 300 DR Rotterdam, The Netherlands; fax: +31-10-4089-468

^* To whom correspondence should be addressed.

Received August 26, 2005

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Interaction of nucleotide excision repair factors--replication protein A (RPA) and Xeroderma pigmentosum complementing group A protein (XPA)--with DNA structures containing nucleotides with bulky photoreactive groups imitating damaged nucleotides was investigated. Efficiency of photoaffinity modification of two proteins by photoreactive DNAs varied depending on DNA structure and type of photoreactive group. The secondary structure of DNA and, first of all, the presence of extended single-stranded parts plays a key role in recognition by RPA. However, it was shown that RPA efficiently interacts with DNA duplex containing a bulky substituent at the 5´-end of a nick. XPA was shown to prefer the nicked DNA; however, this protein was cross-linked with approximately equal efficiency by single-stranded and double-stranded DNA containing a bulky substituent inside the strand. XPA seems to be sensitive not only to the structure of DNA double helix, but also to a bulky group incorporated into DNA. The mechanism of damage recognition in the process of nucleotide excision repair is discussed.

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KEY WORDS: replication protein A, nucleotide excision repair factors, photoaffinity modification, photoreactive oligonucleotides, complexing

DOI: 10.1134/S0006297906030060

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