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Structural basis of nucleic-acid recognition and double-strand unwinding by the essential neuronal protein Pur-alpha.

Weber J, Bao H, Hartlmüller C, Wang Z, Windhager A, Janowski R, Madl T, Jin P, Niessing D - Elife (2016)

Bottom Line: It reveals base-specific recognition and offers a molecular explanation for the effect of point mutations in the 5q31.3 microdeletion syndrome.Complementing in vivo analyses in Drosophila demonstrated the importance of a highly conserved phenylalanine for Pur-alpha's unwinding and neuroprotective function.By uncovering the molecular mechanisms of nucleic-acid binding, this study contributes to understanding the cellular role of Pur-alpha and its implications in neurodegenerative diseases.

View Article: PubMed Central - PubMed

Affiliation: Institute of Structural Biology, Helmholtz Zentrum München - German Research Center for Environmental Health, Neuherberg, Germany.

ABSTRACT
The neuronal DNA-/RNA-binding protein Pur-alpha is a transcription regulator and core factor for mRNA localization. Pur-alpha-deficient mice die after birth with pleiotropic neuronal defects. Here, we report the crystal structure of the DNA-/RNA-binding domain of Pur-alpha in complex with ssDNA. It reveals base-specific recognition and offers a molecular explanation for the effect of point mutations in the 5q31.3 microdeletion syndrome. Consistent with the crystal structure, biochemical and NMR data indicate that Pur-alpha binds DNA and RNA in the same way, suggesting binding modes for tri- and hexanucleotide-repeat RNAs in two neurodegenerative RNAopathies. Additionally, structure-based in vitro experiments resolved the molecular mechanism of Pur-alpha's unwindase activity. Complementing in vivo analyses in Drosophila demonstrated the importance of a highly conserved phenylalanine for Pur-alpha's unwinding and neuroprotective function. By uncovering the molecular mechanisms of nucleic-acid binding, this study contributes to understanding the cellular role of Pur-alpha and its implications in neurodegenerative diseases.

No MeSH data available.


Related in: MedlinePlus

Within the crystal structure the protein-bound DNA anneals with another symmetry-related DNA molecule. Cartoon representation shows Pur-alpha repeat I-II (blue) bound to two DNA molecules (pink) and the symmetry-related Pur-alpha-DNA complex (grey and cyan, respectively). The 5’ ends of the symmetry-related DNA molecules (DNA 1 and 1’) are base pairing (see close-up on the right side).DOI:http://dx.doi.org/10.7554/eLife.11297.009
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fig2s2: Within the crystal structure the protein-bound DNA anneals with another symmetry-related DNA molecule. Cartoon representation shows Pur-alpha repeat I-II (blue) bound to two DNA molecules (pink) and the symmetry-related Pur-alpha-DNA complex (grey and cyan, respectively). The 5’ ends of the symmetry-related DNA molecules (DNA 1 and 1’) are base pairing (see close-up on the right side).DOI:http://dx.doi.org/10.7554/eLife.11297.009

Mentions: Within the crystal lattice the first two bases (G1 and C2) of the 5’-end of DNA 1 are base pairing with the 5’-end of the symmetry related DNA molecule (DNA 1’; Figure 2—figure supplement 2). The cytosine C5 in the middle of the DNA 1 strand is twisted and does not stack with the neighboring guanines (Figure 2E). Instead, F145 from the β-sheet of PUR repeat II stacks with the neighboring guanine G4 and thereby blocks the space for the cytosine C5 (Figure 2E, Video 1).


Structural basis of nucleic-acid recognition and double-strand unwinding by the essential neuronal protein Pur-alpha.

Weber J, Bao H, Hartlmüller C, Wang Z, Windhager A, Janowski R, Madl T, Jin P, Niessing D - Elife (2016)

Within the crystal structure the protein-bound DNA anneals with another symmetry-related DNA molecule. Cartoon representation shows Pur-alpha repeat I-II (blue) bound to two DNA molecules (pink) and the symmetry-related Pur-alpha-DNA complex (grey and cyan, respectively). The 5’ ends of the symmetry-related DNA molecules (DNA 1 and 1’) are base pairing (see close-up on the right side).DOI:http://dx.doi.org/10.7554/eLife.11297.009
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4764581&req=5

fig2s2: Within the crystal structure the protein-bound DNA anneals with another symmetry-related DNA molecule. Cartoon representation shows Pur-alpha repeat I-II (blue) bound to two DNA molecules (pink) and the symmetry-related Pur-alpha-DNA complex (grey and cyan, respectively). The 5’ ends of the symmetry-related DNA molecules (DNA 1 and 1’) are base pairing (see close-up on the right side).DOI:http://dx.doi.org/10.7554/eLife.11297.009
Mentions: Within the crystal lattice the first two bases (G1 and C2) of the 5’-end of DNA 1 are base pairing with the 5’-end of the symmetry related DNA molecule (DNA 1’; Figure 2—figure supplement 2). The cytosine C5 in the middle of the DNA 1 strand is twisted and does not stack with the neighboring guanines (Figure 2E). Instead, F145 from the β-sheet of PUR repeat II stacks with the neighboring guanine G4 and thereby blocks the space for the cytosine C5 (Figure 2E, Video 1).

Bottom Line: It reveals base-specific recognition and offers a molecular explanation for the effect of point mutations in the 5q31.3 microdeletion syndrome.Complementing in vivo analyses in Drosophila demonstrated the importance of a highly conserved phenylalanine for Pur-alpha's unwinding and neuroprotective function.By uncovering the molecular mechanisms of nucleic-acid binding, this study contributes to understanding the cellular role of Pur-alpha and its implications in neurodegenerative diseases.

View Article: PubMed Central - PubMed

Affiliation: Institute of Structural Biology, Helmholtz Zentrum München - German Research Center for Environmental Health, Neuherberg, Germany.

ABSTRACT
The neuronal DNA-/RNA-binding protein Pur-alpha is a transcription regulator and core factor for mRNA localization. Pur-alpha-deficient mice die after birth with pleiotropic neuronal defects. Here, we report the crystal structure of the DNA-/RNA-binding domain of Pur-alpha in complex with ssDNA. It reveals base-specific recognition and offers a molecular explanation for the effect of point mutations in the 5q31.3 microdeletion syndrome. Consistent with the crystal structure, biochemical and NMR data indicate that Pur-alpha binds DNA and RNA in the same way, suggesting binding modes for tri- and hexanucleotide-repeat RNAs in two neurodegenerative RNAopathies. Additionally, structure-based in vitro experiments resolved the molecular mechanism of Pur-alpha's unwindase activity. Complementing in vivo analyses in Drosophila demonstrated the importance of a highly conserved phenylalanine for Pur-alpha's unwinding and neuroprotective function. By uncovering the molecular mechanisms of nucleic-acid binding, this study contributes to understanding the cellular role of Pur-alpha and its implications in neurodegenerative diseases.

No MeSH data available.


Related in: MedlinePlus