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Published on: July 11, 2013
Structure of yeast poly(A) polymerase alone and in complex with 3'-dATP
J Bard1, A M Zhelkovsky, S Helmling
1Boston Biomedical Research Institute, 64 Grove Street, Watertown, MA 02472, USA.
Science (New York, N.Y.)
|August 26, 2000
Summary
The crystal structure of yeast polyadenylate polymerase (PAP) reveals a unique domain arrangement. This structure, bound to a nucleotide analog, provides insights into mRNA polyadenylation.
Area of Science:
- Biochemistry
- Structural Biology
- Molecular Biology
Background:
- Polyadenylate [poly(A)] polymerase (PAP) is essential for adding polyadenosine tails to eukaryotic messenger RNAs (mRNAs).
- Understanding PAP's structure is crucial for elucidating mRNA processing mechanisms.
Purpose of the Study:
- To determine the crystal structure of Saccharomyces cerevisiae polyadenylate polymerase (Pap1).
- To investigate the structural basis of Pap1's enzymatic activity through complex formation with a nucleotide analog.
Main Methods:
- X-ray crystallography was employed to solve the crystal structure of Pap1.
- Structures were determined both for the apoenzyme and in complex with 3'-deoxyadenosine triphosphate (3'-dATP).
Main Results:
- The crystal structure of Pap1 was solved at 2.6 angstrom resolution.
- Pap1 exhibits a three-domain structure encircling the active site, distinct from template-dependent polymerases.
- Two 3'-dATP molecules bind to Pap1, occupying positions for the incoming nucleotide and the mRNA primer's 3' end.
Conclusions:
- The unique domain arrangement of Pap1 provides a structural basis for its non-templated nucleotide addition.
- The binding of 3'-dATP suggests a mechanism for nucleotide incorporation and primer interaction during polyadenylation.
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