Photoreactivation of DNA by an archaeal nucleoprotein Sso7d.

ABSTRACT: Sso7d is a chromosomal protein of hyperthermophilic Archaea. The crystal structure of Sso7d-d(GTAAT(I)UAC)(2) has been clarified at high resolution, showing that the protein binds in the minor groove of DNA, causing a sharp kink of approximately 60 degrees. Recently, we found that photoirradiation of Sso7d and 5-iodouracil-((I)U)-containing 5'-d(GTAAT(I)UAC)-3' efficiently induced the abstraction of hydrogen from the methyl group of T(5) at the kink. In the present study, we found that the photoreactivity of 5-bromouracil ((Br)U)-containing 5'-d(GTAAT(Br)UAC)-3' was enhanced in the presence of Sso7d. Using hypoxanthine (I)-containing 5'-d(ITAAT(Br)UAC)-3', we demonstrated that electron transfer occurs efficiently from Sso7d to DNA. Product analysis showed that Trp-24 of Sso7d, located at t

SUBMITTER: Tashiro R 

PROVIDER: S-EPMC1636510 | biostudies-literature | 2006 Nov

REPOSITORIES: biostudies-literature