Urata Hidehito, Tamaki Chihiro, Matsuno Miki, Wada Shun-ichi, Akagi Masao
Osaka University of Pharmaceutical Sciences, 4-20-1 Nasahara, Takatsuki, Osaka 569-1094, Japan.
Biochem Biophys Res Commun. 2009 Dec 11;390(2):192-5. doi: 10.1016/j.bbrc.2009.08.164. Epub 2009 Sep 2.
We found unusual reactivity of a heterochiral dodecadeoxynucleotide toward EcoRI that contains an unnatural l-nucleotide residue at the 3'-flanking site of the hexameric EcoRI recognition sequence. In this study, the kinetic parameters for the reaction were determined by means of a heterochiral molecular beacon that contains the EcoRI recognition sequence in the stem region and possesses the fluorescent and quenching dyes at the 5'- and 3'-termini, respectively. We found that the heterochiral molecular beacon showed large V(max) and small K(m) values compared to the corresponding homochiral one. This chiral modification is expected to induce a preferable conformational change for binding and catalysis by EcoRI.
