© 2004 The Japanese Biochemical Society
MOLECULAR BIOLOGY |
Kinetic Analysis of Precursor M1 RNA Molecules for Exploring Substrate Specificity of the N-Terminal Catalytic Half of RNase E
1 Department of Chemistry and Center for Molecular Design and Synthesis, Korea Advanced Institute of Science and Technology, Daejeon 305-701, Korea; and 2 Department of Chemistry, Chongju University, Chongju 360-764, Korea
To gain insight into the mechanism by which the sequence at the rne-dependent site of substrate RNA affects the substrate specificity of Escherichia coli RNase E, we performed kinetic analysis of the cleavage of precursor M1 RNA molecules containing various sequences at the rne-dependent site by the N-terminal catalytic half of RNase E (NTH-RNase E). NTH-RNase E displayed higher Km and kcat values for more specific substrates. The retention of single strandedness at the rne-dependent site was essential for cleavage efficiency. Moreover, the loss of single-strandedness was accompanied by a decrease in both the Km and kcat values.
* Present address: Department of Cell Biology, Howard Hughes Medical Institute, Yale University School of Medicine, New Haven, Connecticut 06536, USA.
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