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Daskalova SM, Dedkova LM, Maini R, Talukder P, Bai X, Chowdhury SR, Zhang C, Nangreave RC, Hecht SM. Elongation Factor P Modulates the Incorporation of Structurally Diverse Noncanonical Amino Acids into Escherichia coli Dihydrofolate Reductase. J Am Chem Soc 2023; 145:23600-23608. [PMID: 37871253 PMCID: PMC10762953 DOI: 10.1021/jacs.3c07524] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2023]
Abstract
The introduction of noncanonical amino acids into proteins and peptides has been of great interest for many years and has facilitated the detailed study of peptide/protein structure and mechanism. In addition to numerous nonproteinogenic α-l-amino acids, bacterial ribosome modification has provided the wherewithal to enable the synthesis of peptides and proteins with a much greater range of structural diversity, as has the use of endogenous bacterial proteins in reconstituted protein synthesizing systems. In a recent report, elongation factor P (EF-P), putatively essential for enabling the incorporation of contiguous proline residues into proteins, was shown to facilitate the introduction of an N-methylated amino acid in addition to proline. This finding prompted us to investigate the properties of this protein factor with a broad variety of structurally diverse amino acid analogues using an optimized suppressor tRNAPro that we designed. While these analogues can generally be incorporated into proteins only in systems containing modified ribosomes specifically selected for their incorporation, we found that EF-P could significantly enhance their incorporation into model protein dihydrofolate reductase using wild-type ribosomes. Plausibly, the increased yields observed in the presence of structurally diverse amino acid analogues may result from the formation of a stabilized ribosomal complex in the presence of EF-P that provides more favorable conditions for peptide bond formation. This finding should enable the facile incorporation of a much broader structural variety of amino acid analogues into proteins and peptides using native ribosomes.
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Affiliation(s)
- Sasha M Daskalova
- Biodesign Center for Bioenergetics, and School of Molecular Sciences, Arizona State University, Tempe, Arizona 85287, United States
| | - Larisa M Dedkova
- Biodesign Center for Bioenergetics, and School of Molecular Sciences, Arizona State University, Tempe, Arizona 85287, United States
| | - Rumit Maini
- Biodesign Center for Bioenergetics, and School of Molecular Sciences, Arizona State University, Tempe, Arizona 85287, United States
| | - Poulami Talukder
- Biodesign Center for Bioenergetics, and School of Molecular Sciences, Arizona State University, Tempe, Arizona 85287, United States
| | - Xiaoguang Bai
- Biodesign Center for Bioenergetics, and School of Molecular Sciences, Arizona State University, Tempe, Arizona 85287, United States
| | - Sandipan Roy Chowdhury
- Biodesign Center for Bioenergetics, and School of Molecular Sciences, Arizona State University, Tempe, Arizona 85287, United States
| | - Chao Zhang
- Biodesign Center for Bioenergetics, and School of Molecular Sciences, Arizona State University, Tempe, Arizona 85287, United States
| | - Ryan C Nangreave
- Biodesign Center for Bioenergetics, and School of Molecular Sciences, Arizona State University, Tempe, Arizona 85287, United States
| | - Sidney M Hecht
- Biodesign Center for Bioenergetics, and School of Molecular Sciences, Arizona State University, Tempe, Arizona 85287, United States
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Hecht SM. Expansion of the Genetic Code Through the Use of Modified Bacterial Ribosomes. J Mol Biol 2022; 434:167211. [PMID: 34419431 PMCID: PMC9990327 DOI: 10.1016/j.jmb.2021.167211] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2021] [Revised: 08/06/2021] [Accepted: 08/09/2021] [Indexed: 11/29/2022]
Abstract
Biological protein synthesis is mediated by the ribosome, and employs ~20 proteinogenic amino acids as building blocks. Through the use of misacylated tRNAs, presently accessible by any of several strategies, it is now possible to employ in vitro and in vivo protein biosynthesis to elaborate proteins containing a much larger variety of amino acid building blocks. However, the incorporation of this broader variety of amino acids is limited to those species utilized by the ribosome. As a consequence, virtually all of the substrates utilized over time have been L-α-amino acids. In recent years, a variety of structural and biochemical studies have provided important insights into those regions of the 23S ribosomal RNA that are involved in peptide bond formation. Subsequent experiments, involving the randomization of key regions of 23S rRNA required for peptide bond formation, have afforded libraries of E. coli harboring plasmids with the rrnB gene modified in the key regions. Selections based on the use of modified puromycin derivatives with altered amino acids then identified clones uniquely sensitive to individual puromycin derivatives. These clones often recognized misacylated tRNAs containing altered amino acids similar to those in the modified puromycins, and incorporated the amino acid analogues into proteins. In this fashion, it has been possible to realize the synthesis of proteins containing D-amino acids, β-amino acids, phosphorylated amino acids, as well as long chain and cyclic amino acids in which the nucleophilic amino group is not in the α-position. Of special interest have been dipeptides and dipeptidomimetics of diverse utility.
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Affiliation(s)
- Sidney M Hecht
- Center for BioEnergetics, Biodesign Institute, Arizona State University, Tempe, AZ 85287, USA; School of Molecular Sciences, Arizona State University, Tempe, AZ 85287, USA.
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Zhang C, Talukder P, Dedkova LM, Hecht SM. Facilitated synthesis of proteins containing modified dipeptides. Bioorg Med Chem 2021; 41:116210. [PMID: 34022527 DOI: 10.1016/j.bmc.2021.116210] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2021] [Revised: 04/29/2021] [Accepted: 05/04/2021] [Indexed: 11/29/2022]
Abstract
The elaboration of peptides and proteins containing non-proteinogenic amino acids has been realized using several complementary strategies, including chemical synthesis, ribosome- or non-ribosome-mediated elaboration, intein-mediated polypeptide rearrangements, or some combination of these strategies. All of these have strengths and limitations, and significant efforts have been focused on minimizing the effects of limitations, to improve the overall utility of individual strategies. Our laboratory has studied ribosomally mediated peptide and protein synthesis involving a wide variety of non-proteinogenic amino acids, and in recent years we have described a novel strategy for the selection of modified bacterial ribosomes. These modified ribosomes have enabled the incorporation into peptides and proteins of numerous modified amino acids not accessible using wild-type ribosomes. This has included d-amino acids, β-amino acids, dipeptides and dipeptidomimetic species, as well as phosphorylated amino acids. Presently, we have considered novel strategies for incorporating non-proteinogenic amino acids in improved yields. This has included the incorporation of non-proteinogenic amino acids into contiguous positions, a transformation known to be challenging. We demonstrate the preparation of this type of protein modification by utilizing a suppressor tRNACUA activated with a dipeptide consisting of two identical non-proteinogenic amino acids, in the presence of modified ribosomes selected to recognize such dipeptides. Also, we demonstrate that the use of bis-aminoacylated suppressor tRNAs, shown previously to increase protein yields significantly in vitro, can be extended to the use of non-proteinogenic amino acids.
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Affiliation(s)
- Chao Zhang
- Biodesign Center for BioEnergetics and School of Molecular Sciences, Arizona State University, Tempe, AZ 85287, United States
| | - Poulami Talukder
- Biodesign Center for BioEnergetics and School of Molecular Sciences, Arizona State University, Tempe, AZ 85287, United States
| | - Larisa M Dedkova
- Biodesign Center for BioEnergetics and School of Molecular Sciences, Arizona State University, Tempe, AZ 85287, United States
| | - Sidney M Hecht
- Biodesign Center for BioEnergetics and School of Molecular Sciences, Arizona State University, Tempe, AZ 85287, United States
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Corbella M, Liao Q, Moreira C, Parracino A, Kasson PM, Kamerlin SCL. The N-terminal Helix-Turn-Helix Motif of Transcription Factors MarA and Rob Drives DNA Recognition. J Phys Chem B 2021; 125:6791-6806. [PMID: 34137249 PMCID: PMC8279559 DOI: 10.1021/acs.jpcb.1c00771] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
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DNA-binding proteins
play an important role in gene regulation
and cellular function. The transcription factors MarA and Rob are
two homologous members of the AraC/XylS family that regulate multidrug
resistance. They share a common DNA-binding domain, and Rob possesses
an additional C-terminal domain that permits binding of low-molecular
weight effectors. Both proteins possess two helix-turn-helix (HTH)
motifs capable of binding DNA; however, while MarA interacts with
its promoter through both HTH-motifs, prior studies indicate that
Rob binding to DNA via a single HTH-motif is sufficient for tight
binding. In the present work, we perform microsecond time scale all-atom
simulations of the binding of both transcription factors to different
DNA sequences to understand the determinants of DNA recognition and
binding. Our simulations characterize sequence-dependent changes in
dynamical behavior upon DNA binding, showcasing the role of Arg40
of the N-terminal HTH-motif in allowing for specific tight binding.
Finally, our simulations demonstrate that an acidic C-terminal loop
of Rob can control the DNA binding mode, facilitating interconversion
between the distinct DNA binding modes observed in MarA and Rob. In
doing so, we provide detailed molecular insight into DNA binding and
recognition by these proteins, which in turn is an important step
toward the efficient design of antivirulence agents that target these
proteins.
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Affiliation(s)
- Marina Corbella
- Science for Life Laboratory, Department of Chemistry-BMC, Uppsala University, Uppsala, S-751 23, Sweden
| | - Qinghua Liao
- Science for Life Laboratory, Department of Chemistry-BMC, Uppsala University, Uppsala, S-751 23, Sweden
| | - Cátia Moreira
- Science for Life Laboratory, Department of Chemistry-BMC, Uppsala University, Uppsala, S-751 23, Sweden
| | - Antonietta Parracino
- Science for Life Laboratory, Department of Chemistry-BMC, Uppsala University, Uppsala, S-751 23, Sweden
| | - Peter M Kasson
- Science for Life Laboratory, Department of Cell and Molecular Biology, Uppsala University, Uppsala, S-65124, Sweden.,Departments of Molecular Physiology and Biomedical Engineering, University of Virginia, Charlottesville, Virginia 22908, United States
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