Gene/Protein
Disease
Symptom
Drug
Enzyme
Compound
Pivot Concepts:
Gene/Protein
Disease
Symptom
Drug
Enzyme
Compound
Target Concepts:
Gene/Protein
Disease
Symptom
Drug
Enzyme
Compound
Query: EC:3.1.26.4 (
RNase H
)
2,751
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
The crystal structures of protein-nucleic acid complexes are commonly determined using selenium-derivatized proteins via MAD or
SAD
phasing. Here, the first protein-nucleic acid complex structure determined using selenium-derivatized nucleic acids is reported. The
RNase H
-RNA/DNA complex is used as an example to demonstrate the proof of principle. The high-resolution crystal structure indicates that this selenium replacement results in a local subtle unwinding of the RNA/DNA substrate duplex, thereby shifting the RNA scissile phosphate closer to the transition state of the enzyme-catalyzed reaction. It was also observed that the scissile phosphate forms a hydrogen bond to the water nucleophile and helps to position the water molecule in the structure. Consistently, it was discovered that the substitution of a single O atom by a Se atom in a guide DNA sequence can largely accelerate
RNase H
catalysis. These structural and catalytic studies shed new light on the guide-dependent RNA cleavage.
...
PMID:Novel complex MAD phasing and RNase H structural insights using selenium oligonucleotides. 2453 69
