scholarly journals The design and structural characterization of a synthetic pentatricopeptide repeat protein

2015 ◽  
Vol 71 (2) ◽  
pp. 196-208 ◽  
Author(s):  
Benjamin S. Gully ◽  
Kunal R. Shah ◽  
Mihwa Lee ◽  
Kate Shearston ◽  
Nicole M. Smith ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Binding Proteins ◽  
Rna Binding ◽  
De Novo ◽  
Rna Binding Proteins ◽  
Specific Binding ◽  
Consensus Sequence ◽  
Pentatricopeptide Repeat ◽  
Ppr Protein ◽  
Ppr Proteins

Proteins of the pentatricopeptide repeat (PPR) superfamily are characterized by tandem arrays of a degenerate 35-amino-acid α-hairpin motif. PPR proteins are typically single-stranded RNA-binding proteins with essential roles in organelle biogenesis, RNA editing and mRNA maturation. A modular, predictable code for sequence-specific binding of RNA by PPR proteins has recently been revealed, which opens the door to thede novodesign of bespoke proteins with specific RNA targets, with widespread biotechnological potential. Here, the design and production of a synthetic PPR protein based on a consensus sequence and the determination of its crystal structure to 2.2 Å resolution are described. The crystal structure displays helical disorder, resulting in electron density representing an infinite superhelical PPR protein. A structural comparison with related tetratricopeptide repeat (TPR) proteins, and with native PPR proteins, reveals key roles for conserved residues in directing the structure and function of PPR proteins. The designed proteins have high solubility and thermal stability, and can form long tracts of PPR repeats. Thus, consensus-sequence synthetic PPR proteins could provide a suitable backbone for the design of bespoke RNA-binding proteins with the potential for high specificity.

scholarly journals In vivo stabilization of endogenous chloroplast RNAs by customized artificial pentatricopeptide repeat proteins

2020 ◽  
Author(s):  
Nikolay Manavski ◽  
Louis-Valentin Meteignier ◽  
Margarita Rojas ◽  
Andreas Brachmann ◽  
Alice Barkan ◽  
...  
Keyword(s):  
Rna Binding ◽  
Rna Binding Proteins ◽  
Sequence Specificity ◽  
Pentatricopeptide Repeat ◽  
Functional Capabilities ◽  
Ppr Protein ◽  
Repeat Proteins ◽  
Ppr Proteins ◽  
Physical Barriers

ABSTRACTPentatricopeptide repeat (PPR) proteins are helical repeat-proteins that bind RNA in a modular fashion with a sequence-specificity that can be manipulated by the use of an amino acid code. As such, PPR repeats are promising scaffolds for the design of RNA binding proteins for synthetic biology applications. However, the in vivo functional capabilities of artificial PPR proteins built from consensus PPR motifs are just starting to be explored. Here, we report in vivo functions of an artificial PPR protein, dPPRrbcL, made of consensus PPR motifs that were designed to bind a sequence near the 5’ end of rbcL transcripts in Arabidopsis chloroplasts. We used a functional complementation assay to demonstrate that this protein bound its intended RNA target with specificity in vivo and that it substituted for a natural PPR protein by stabilizing processed rbcL mRNA. We targeted a second protein of analogous design to the petL 5’ UTR, where it substituted for the native stabilizing PPR protein PGR3, albeit inefficiently. These results showed that artificial PPRs can be engineered to functionally mimic the class of native PPR proteins that serve as physical barriers against exoribonucleases.

scholarly journals A synthetic RNA editing factor edits its target site in chloroplasts and bacteria

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Santana Royan ◽  
Bernard Gutmann ◽  
Catherine Colas des Francs-Small ◽  
Suvi Honkanen ◽  
Jason Schmidberger ◽  
...  
Keyword(s):  
Rna Editing ◽  
Rna Binding ◽  
Rna Binding Proteins ◽  
Target Sequence ◽  
Pentatricopeptide Repeat ◽  
Binding Assays ◽  
E Coli ◽  
Ppr Protein ◽  
Ppr Proteins

AbstractMembers of the pentatricopeptide repeat (PPR) protein family act as specificity factors in C-to-U RNA editing. The expansion of the PPR superfamily in plants provides the sequence variation required for design of consensus-based RNA-binding proteins. We used this approach to design a synthetic RNA editing factor to target one of the sites in the Arabidopsis chloroplast transcriptome recognised by the natural editing factor CHLOROPLAST BIOGENESIS 19 (CLB19). We show that our synthetic editing factor specifically recognises the target sequence in in vitro binding assays. The designed factor is equally specific for the target rpoA site when expressed in chloroplasts and in the bacterium E. coli. This study serves as a successful pilot into the design and application of programmable RNA editing factors based on plant PPR proteins.

scholarly journals A Pentatricopeptide Repeat Protein in the Plasmodium apicoplast is essential and shows sequence-specific RNA binding

2018 ◽  
Author(s):  
Joanna L. Hicks ◽  
Imen Lassadi ◽  
Emma Carpenter ◽  
Madeleine Eno ◽  
Alexandros Vardakis ◽  
...  
Keyword(s):  
Rna Processing ◽  
Rna Binding ◽  
Specific Binding ◽  
Binding Motif ◽  
Pentatricopeptide Repeat ◽  
Rna Sequences ◽  
Rnase Protection ◽  
Ppr Protein ◽  
Biochemical Characterisation ◽  
Ppr Proteins

ABSTRACTThe malaria parasite Plasmodium and other apicomplexans such as Toxoplasma evolved from photosynthetic organisms and contain an essential, remnant plastid termed the apicoplast. Transcription of the apicoplast genome is polycistronic with extensive RNA processing. Little is known about the mechanism of post-transcriptional processing. In plant chloroplasts, post-transcriptional RNA processing is controlled by multiple pentatricopeptide repeat (PPR) proteins. Here, we present the biochemical characterisation of the single apicoplast-targeted PPR protein. Apicoplast PPR1 is essential, and binds specific RNA sequences corresponding with previously characterized RNA processing sites. We identify the specific binding motif of PPR1. In RNAse protection assays, PPR1 shields apicoplast transcripts from ribonuclease degradation. Our results show that apicoplast RNA processing is under the control of a single protein, thus presenting an Achilles’ heel for the development of new anti-malarial drugs.

scholarly journals Searching for a Match: Structure, Function and Application of Sequence-Specific RNA-Binding Proteins

2019 ◽  
Vol 60 (9) ◽  
pp. 1927-1938 ◽  
Author(s):  
Lauren K Dedow ◽  
Julia Bailey-Serres
Keyword(s):  
Gene Regulation ◽  
Binding Proteins ◽  
Rna Binding ◽  
Rna Binding Proteins ◽  
Sequence Specificity ◽  
Pentatricopeptide Repeat ◽  
Rna Sequences ◽  
Regulatory Processes ◽  
Ppr Proteins ◽  
Modular Structures

Abstract Plants encode over 1800 RNA-binding proteins (RBPs) that modulate a myriad of steps in gene regulation from chromatin organization to translation, yet only a small number of these proteins and their target transcripts have been functionally characterized. Two classes of eukaryotic RBPs, pentatricopeptide repeat (PPR) and pumilio/fem-3 binding factors (PUF), recognize and bind to specific sequential RNA sequences through protein–RNA interactions. These modular proteins possess helical structural units containing key residues with high affinity for specific nucleotides, whose sequential order determines binding to a specific target RNA sequence. PPR proteins are nucleus-encoded, but largely regulate post-transcriptional gene regulation within plastids and mitochondria, including splicing, translation and RNA editing. Plant PUFs are involved in gene regulatory processes within the cell nucleus and cytoplasm. The modular structures of PPRs and PUFs that determine sequence specificity has facilitated identification of their RNA targets and biological functions. The protein-based RNA-targeting of PPRs and PUFs contrasts to the prokaryotic cluster regularly interspaced short palindromic repeats (CRISPR)-associated proteins (Cas) that target RNAs in prokaryotes. Together the PPR, PUF and CRISPR-Cas systems provide varied opportunities for RNA-targeted engineering applications.

scholarly journals PPR20 Is Required for the cis-Splicing of Mitochondrial nad2 Intron 3 and Seed Development in Maize

2019 ◽  
Vol 61 (2) ◽  
pp. 370-380 ◽  
Author(s):  
Yan-Zhuo Yang ◽  
Shuo Ding ◽  
Yong Wang ◽  
Hong-Chun Wang ◽  
Xin-Yuan Liu ◽  
...  
Keyword(s):  
Seed Development ◽  
Rna Binding ◽  
Rna Binding Proteins ◽  
Endosperm Development ◽  
Binding Activity ◽  
Pentatricopeptide Repeat ◽  
Ppr Protein ◽  
Exact Function ◽  
Ppr Proteins ◽  
P Type

Abstract Pentatricopeptide repeat (PPR) proteins are helical repeat RNA-binding proteins that function in RNA processing by conferring sequence-specific RNA-binding activity. Owing to the lethality of PPR mutants, functions of many PPR proteins remain obscure. In this study, we report the function of PPR20 in intron splicing in mitochondria and its role in maize seed development. PPR20 is a P-type PPR protein targeted to mitochondria. The ppr20 mutants display slow embryo and endosperm development. Null mutation of PPR20 severely reduces the cis-splicing of mitochondrial nad2 intron 3, resulting in reduction in the assembly and activity of mitochondrial complex I. The ppr20-35 allele with a Mu insertion in the N-terminal region shows a much weaker phenotype. Molecular analyses revealed that the mutant produces a truncated transcript, coding for PPR20ΔN120 lacking the N-terminal 120 amino acids. Subcellular localization revealed that PPR20ΔN120:GFP is able to target to mitochondria as well, suggesting the sequence diversity of the mitochondrial targeting peptides. Another mutant zm_mterf15 was also found to be impaired in the splicing of mitochondrial nad2 intron 3. Further analyses are required to identify the exact function of PPR20 and Zm_mTERF15 in the splicing of nad2 intron 3.

scholarly journals De-novo protein function prediction using DNA binding and RNA binding proteins as a test case

2016 ◽  
Vol 7 (1) ◽  
Author(s):  
Sapir Peled ◽  
Olga Leiderman ◽  
Rotem Charar ◽  
Gilat Efroni ◽  
Yaron Shav-Tal ◽  
...  
Keyword(s):  
Dna Binding ◽  
Protein Function ◽  
Binding Proteins ◽  
Rna Binding ◽  
De Novo ◽  
Rna Binding Proteins ◽  
Protein Function Prediction ◽  
Function Prediction ◽  
Test Case

scholarly journals De novo design of RNA-binding proteins with a prion-like domain related to ALS/FTD proteinopathies

2017 ◽  
Vol 7 (1) ◽  
Author(s):  
Kana Mitsuhashi ◽  
Daisuke Ito ◽  
Kyoko Mashima ◽  
Munenori Oyama ◽  
Shinichi Takahashi ◽  
...  
Keyword(s):  
Binding Proteins ◽  
Rna Binding ◽  
De Novo ◽  
Rna Binding Proteins ◽  
De Novo Design

PUB1 is a major nuclear and cytoplasmic polyadenylated RNA-binding protein in Saccharomyces cerevisiae

1993 ◽  
Vol 13 (10) ◽  
pp. 6102-6113
Author(s):  
J T Anderson ◽  
M R Paddy ◽  
M S Swanson
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Binding Proteins ◽  
Rna Binding ◽  
Rna Binding Proteins ◽  
Uv Light ◽  
Binding Protein ◽  
Consensus Sequence ◽  
Rna Binding Protein ◽  
Polyadenylated Rna ◽  
Polyadenylated Rnas

Proteins that directly associate with nuclear polyadenylated RNAs, or heterogeneous nuclear RNA-binding proteins (hnRNPs), and those that associate with cytoplasmic mRNAs, or mRNA-binding proteins (mRNPs), play important roles in regulating gene expression at the posttranscriptional level. Previous work with a variety of eukaryotic cells has demonstrated that hnRNPs are localized predominantly within the nucleus whereas mRNPs are cytoplasmic. While studying proteins associated with polyadenylated RNAs in Saccharomyces cerevisiae, we discovered an abundant polyuridylate-binding protein, PUB1, which appears to be both an hnRNP and an mRNP. PUB1 and PAB1, the polyadenylate tail-binding protein, are the two major proteins cross-linked by UV light to polyadenylated RNAs in vivo. The deduced primary structure of PUB1 indicates that it is a member of the ribonucleoprotein consensus sequence family of RNA-binding proteins and is structurally related to the human hnRNP M proteins. Even though the PUB1 protein is a major cellular polyadenylated RNA-binding protein, it is nonessential for cell growth. Indirect cellular immunofluorescence combined with digital image processing allowed a detailed comparison of the intracellular distributions of PUB1 and PAB1. While PAB1 is predominantly, and relatively uniformly, distributed within the cytoplasm, PUB1 is localized in a nonuniform pattern throughout both the nucleus and the cytoplasm. The cytoplasmic distribution of PUB1 is considerably more discontinuous than that of PAB1. Furthermore, sucrose gradient sedimentation analysis demonstrates that PAB1 cofractionates with polyribosomes whereas PUB1 does not. These results suggest that PUB1 is both an hnRNP and an mRNP and that it may be stably bound to a translationally inactive subpopulation of mRNAs within the cytoplasm.

scholarly journals Crystal Structure of a Variant PAM2 Motif of LARP4B Bound to the MLLE Domain of PABPC1

Biomolecules ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 872 ◽  
Author(s):  
Clemens Grimm ◽  
Jann-Patrick Pelz ◽  
Cornelius Schneider ◽  
Katrin Schäffler ◽  
Utz Fischer
Keyword(s):  
Crystal Structure ◽  
Binding Proteins ◽  
Rna Binding ◽  
Rna Binding Proteins ◽  
Turnover Rates ◽  
Mrna Transcription ◽  
Terminal Part ◽  
Protein Output

Eukaryotic cells determine the protein output of their genetic program by regulating mRNA transcription, localization, translation and turnover rates. This regulation is accomplished by an ensemble of RNA-binding proteins (RBPs) that bind to any given mRNA, thus forming mRNPs. Poly(A) binding proteins (PABPs) are prominent members of virtually all mRNPs that possess poly(A) tails. They serve as multifunctional scaffolds, allowing the recruitment of diverse factors containing a poly(A)-interacting motif (PAM) into mRNPs. We present the crystal structure of the variant PAM motif (termed PAM2w) in the N-terminal part of the positive translation factor LARP4B, which binds to the MLLE domain of the poly(A) binding protein C1 cytoplasmic 1 (PABPC1). The structural analysis, along with mutational studies in vitro and in vivo, uncovered a new mode of interaction between PAM2 motifs and MLLE domains.

scholarly journals Identification of Pentatricopeptide Repeat Proteins in the Model OrganismDictyostelium discoideum

2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Sam Manna ◽  
Jessica Brewster ◽  
Christian Barth
Keyword(s):  
Dictyostelium Discoideum ◽  
Rna Binding ◽  
Rna Binding Proteins ◽  
Gene Products ◽  
Antisense Inhibition ◽  
Pentatricopeptide Repeat ◽  
Repeat Proteins ◽  
Ppr Proteins ◽  
Pentatricopeptide Repeat Proteins ◽  
Encoding Genes

Pentatricopeptide repeat (PPR) proteins are RNA binding proteins with functions in organelle RNA metabolism. They are found in all eukaryotes but have been most extensively studied in plants. We report on the identification of 12 PPR-encoding genes in the genome of the protistDictyostelium discoideum, with potential homologs in other members of the same lineage and some predicted novel functions for the encoded gene products in protists. For one of the gene products, we show that it localizes to the mitochondria, and we also demonstrate that antisense inhibition of its expression leads to slower growth, a phenotype associated with mitochondrial dysfunction.

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