Seven sets of protein target sites, which occur in several gene promoters, have been analyzed. The results suggest that there is a possible mode of specific recognition of double-helical nucleic acids by proteins. This recognition mode is related to a special topological property of double-helical DNA, which is termed base spatial pattern (BSP) of DNA segment. BSP is the spatial topological property determined only by the spatial arrangement of the bases on double-helical DNA segment.
LI Xuqing & LIU CiquanDepartment of Computer Science, Kunming University of Science and Technology, Kunming 650041, China
In order to understand the behavior of RNAs with large bulges in solution, molecular dynamics was performed on the RNA molecule in water with A6 bulge. The result of simulation showed that nonstacked conformation is the main conformation in large bulges, and the backbone of large bulge is of great conformational flexibility, but bulges-induced bends are relatively rigid. The fluctuation in bulge has little influence on the bend angle of RNAs.
LIANG Chongrong & LIU CiquanKey Laboratory of Cellular & Molecular Evolution, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming 650223, China
The theoretical model construction of mRNA hairpin structure and single-stranded structure as well as the simulation studies on RNA structure determined by the X-ray crystal diffraction and nuclear magnetic resonance revealed that in translation, after mRNA being unfolded into single-stranded structure, its topological configuration was closely correlative with the original hairpin structure. The conformational features of single-stranded mRNA appeared as helical regions alternating with curly regions to different extents, which might exert the influence on the folding of nascent polypeptide by various regulating effects including different translational rates.
LIU Shuqun & LIU CiquanKunming Institute of Zoology, Chinese Academy of Sciences, Kunming 650223, China
