1
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Bick T, Dominiak PM, Wendler P. Exploiting the full potential of cryo-EM maps. BBA ADVANCES 2024; 5:100113. [PMID: 38292063 PMCID: PMC10825613 DOI: 10.1016/j.bbadva.2024.100113] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2023] [Revised: 01/04/2024] [Accepted: 01/05/2024] [Indexed: 02/01/2024] Open
Abstract
The Coulomb potential maps generated by electron microscopy (EM) experiments contain not only information about the position but also about the charge state of the atom. This feature of EM maps allows the identification of specific ions and the protonation state of amino acid side chains in the sample. Here, we summarize qualitative observations of charges in EM maps, discuss the difficulties in interpreting the charge in Coulomb potential maps with respect to distinguishing it from radiation damage, and outline considerations to implement the correct charge in fitting algorithms.
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Affiliation(s)
- Thomas Bick
- Institute of Biochemistry and Biology, Department of Biochemistry, University of Potsdam, Karl-Liebknecht Strasse 24-25, 14476 Potsdam Golm, Germany
| | - Paulina M. Dominiak
- Biological and Chemical Research Centre, Faculty of Chemistry, University of Warsaw, ul. Żwirki i Wigury 101, 02-089 Warsaw, Poland
| | - Petra Wendler
- Institute of Biochemistry and Biology, Department of Biochemistry, University of Potsdam, Karl-Liebknecht Strasse 24-25, 14476 Potsdam Golm, Germany
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2
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Aziz M, Ejaz SA, Alsfouk BA, Sultan A, Li C. Identification of potential inhibitors against E.coli via novel approaches based on deep learning and quantum mechanics-based atomistic investigations. Arch Biochem Biophys 2023; 747:109761. [PMID: 37734644 DOI: 10.1016/j.abb.2023.109761] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2023] [Revised: 08/31/2023] [Accepted: 09/18/2023] [Indexed: 09/23/2023]
Abstract
Currently, drug resistance to commercially available antibiotics is imparting negative consequences to global health, and the development of novel antibiotics in a timely manner is a prime need of the hour. In the current study, an e-pharmacophore model was built using the 3D structure of DNA gyrase in complex with a standard inhibitor. The generated model was subjected to a pharmacophore based virtual screening against 45,257,086 molecules having 223,460,579 conformers available in MCULE database. Pharmacophore based screening retrieved eight molecules as top hit based on pharmacophoric features in comparison to standard inhibitors. Afterward, all eight compounds were subjected molecular docking based on deep learning algorithm. The molecular docking revealed that compound MCULE-6042843173 and MCULE-2362244223 had significant binding orientation inside active pocket of targeted protein with binding affinity of -9.52 and -9.24 kcal/mol respectively. In addition, density functional theory studies (DFT) were performed to evaluate quantum mechanics of top ranked compounds which were investigated through quantum mechanics (QM) computations which strongly assisted the findings of other in-silico investigations. Consequently, the MCULE-6042843173 and MCULE-2362244223 were subjected to MD simulation studies for evaluation of stability, hydrogen bond analysis, van der Waals interactions, and the contact profile of compounds with targeted amino acid residues. Findings of current study suggested MCULE-6042843173 and MCULE-2362244223 as potential and novel inhibitor of DNA Gyrase enzyme.
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Affiliation(s)
- Mubashir Aziz
- Department of Pharmaceutical Chemistry, Faculty of Pharmacy, The Islamia University of Bahawalpur, Bahawalpur, 63100, Pakistan
| | - Syeda Abida Ejaz
- Department of Pharmaceutical Chemistry, Faculty of Pharmacy, The Islamia University of Bahawalpur, Bahawalpur, 63100, Pakistan.
| | - Bshra A Alsfouk
- Department of Pharmaceutical Sciences, College of Pharmacy, Princess Nourah Bint Abdulrahman University, P.O Box 84428, Riyadh, 11671, Saudi Arabia
| | - Ahlam Sultan
- Department of Pharmaceutical Sciences, College of Pharmacy, Princess Nourah Bint Abdulrahman University, P.O Box 84428, Riyadh, 11671, Saudi Arabia
| | - Chen Li
- Department of Biology, Chemistry, Pharmacy, Free University of Berlin, Berlin, 14195, Germany.
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3
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Ravera S, Nicola JP, Salazar-De Simone G, Sigworth FJ, Karakas E, Amzel LM, Bianchet MA, Carrasco N. Structural insights into the mechanism of the sodium/iodide symporter. Nature 2022; 612:795-801. [PMID: 36517601 PMCID: PMC10501339 DOI: 10.1038/s41586-022-05530-2] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2022] [Accepted: 11/04/2022] [Indexed: 12/15/2022]
Abstract
The sodium/iodide symporter (NIS) is the essential plasma membrane protein that mediates active iodide (I-) transport into the thyroid gland, the first step in the biosynthesis of the thyroid hormones-the master regulators of intermediary metabolism. NIS couples the inward translocation of I- against its electrochemical gradient to the inward transport of Na+ down its electrochemical gradient1,2. For nearly 50 years before its molecular identification3, NIS was the molecule at the centre of the single most effective internal radiation cancer therapy: radioiodide (131I-) treatment for thyroid cancer2. Mutations in NIS cause congenital hypothyroidism, which must be treated immediately after birth to prevent stunted growth and cognitive deficiency2. Here we report three structures of rat NIS, determined by single-particle cryo-electron microscopy: one with no substrates bound; one with two Na+ and one I- bound; and one with one Na+ and the oxyanion perrhenate bound. Structural analyses, functional characterization and computational studies show the substrate-binding sites and key residues for transport activity. Our results yield insights into how NIS selects, couples and translocates anions-thereby establishing a framework for understanding NIS function-and how it transports different substrates with different stoichiometries and releases substrates from its substrate-binding cavity into the cytosol.
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Affiliation(s)
- Silvia Ravera
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN, USA
| | - Juan Pablo Nicola
- Department of Clinical Biochemistry, National University of Córdoba, Córdoba, Argentina
| | | | - Fred J Sigworth
- Department of Cellular and Molecular Physiology, Yale School of Medicine, New Haven, CT, USA
| | - Erkan Karakas
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN, USA
| | - L Mario Amzel
- Department of Biophysics and Biophysical Chemistry, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Mario A Bianchet
- Department of Biophysics and Biophysical Chemistry, Johns Hopkins University School of Medicine, Baltimore, MD, USA
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Nancy Carrasco
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN, USA.
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4
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Wang J, Liu J, Gisriel CJ, Wu S, Maschietto F, Flesher DA, Lolis E, Lisi GP, Brudvig GW, Xiong Y, Batista VS. How to correct relative voxel scale factors for calculations of vector-difference Fourier maps in cryo-EM. J Struct Biol 2022; 214:107902. [PMID: 36202310 DOI: 10.1016/j.jsb.2022.107902] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2022] [Revised: 08/23/2022] [Accepted: 09/28/2022] [Indexed: 12/05/2022]
Abstract
The atomic coordinates derived from cryo-electron microscopy (cryo-EM) maps can be inaccurate when the voxel scaling factors are not properly calibrated. Here, we describe a method for correcting relative voxel scaling factors between pairs of cryo-EM maps for the same or similar structures that are expanded or contracted relative to each other. We find that the correction of scaling factors reduces the amplitude differences of Fourier-inverted structure factors from voxel-rescaled maps by up to 20-30%, as shown by two cryo-EM maps of the SARS-CoV-2 spike protein measured at pH 4.0 and pH 8.0. This allows for the calculation of the difference map after properly scaling, revealing differences between the two structures for individual amino acid residues. Unexpectedly, the analysis uncovers two previously overlooked differences of amino acid residues in structures and their local structural changes. Furthermore, we demonstrate the method as applied to two cryo-EM maps of monomeric apo-photosystem II from the cyanobacteria Synechocystis sp. PCC 6803 and Thermosynechococcus elongatus. The resulting difference maps reveal many changes in the peripheral transmembrane PsbX subunit between the two species.
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Affiliation(s)
- Jimin Wang
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT 06536, USA.
| | - Jinchan Liu
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT 06536, USA
| | | | - Shenping Wu
- Department of Pharmacology, Yale University, New Haven, CT 06520-8066, USA
| | | | - David A Flesher
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT 06536, USA
| | - Elias Lolis
- Department of Pharmacology, Yale University, New Haven, CT 06520-8066, USA
| | - George P Lisi
- Department of Molecular and Cell Biology and Biochemistry, Brown University, Providence, RI 02912, USA
| | - Gary W Brudvig
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT 06536, USA; Department of Chemistry, Yale University, New Haven, CT 06511-8499, USA
| | - Yong Xiong
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT 06536, USA
| | - Victor S Batista
- Department of Chemistry, Yale University, New Haven, CT 06511-8499, USA
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5
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Wang J, Shi Y, Reiss K, Maschietto F, Lolis E, Konigsberg WH, Lisi GP, Batista VS. Structural Insights into Binding of Remdesivir Triphosphate within the Replication-Transcription Complex of SARS-CoV-2. Biochemistry 2022; 61:1966-1973. [PMID: 36044776 PMCID: PMC9469760 DOI: 10.1021/acs.biochem.2c00341] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2022] [Revised: 08/18/2022] [Indexed: 01/18/2023]
Abstract
Remdesivir is an adenosine analogue that has a cyano substitution in the C1' position of the ribosyl moiety and a modified base structure to stabilize the linkage of the base to the C1' atom with its strong electron-withdrawing cyano group. Within the replication-transcription complex (RTC) of SARS-CoV-2, the RNA-dependent RNA polymerase nsp12 selects remdesivir monophosphate (RMP) over adenosine monophosphate (AMP) for nucleotide incorporation but noticeably slows primer extension after the added RMP of the RNA duplex product is translocated by three base pairs. Cryo-EM structures have been determined for the RTC with RMP at the nucleotide-insertion (i) site or at the i + 1, i + 2, or i + 3 sites after product translocation to provide a structural basis for a delayed-inhibition mechanism by remdesivir. In this study, we applied molecular dynamics (MD) simulations to extend the resolution of structures to the measurable maximum that is intrinsically limited by MD properties of these complexes. Our MD simulations provide (i) a structural basis for nucleotide selectivity of the incoming substrates of remdesivir triphosphate over adenosine triphosphate and of ribonucleotide over deoxyribonucleotide, (ii) new detailed information on hydrogen atoms involved in H-bonding interactions between the enzyme and remdesivir, and (iii) direct information on the catalytically active complex that is not easily captured by experimental methods. Our improved resolution of interatomic interactions at the nucleotide-binding pocket between remedesivir and the polymerase could help to design a new class of anti-SARS-CoV-2 inhibitors.
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Affiliation(s)
- Jimin Wang
- Department
of Molecular Biophysics and Biochemistry, Yale University, New Haven, Connecticut 06520-8114, United States
| | - Yuanjun Shi
- Department
of Chemistry, Yale University, New Haven, Connecticut 06520-8499, United States
| | - Krystle Reiss
- Department
of Chemistry, Yale University, New Haven, Connecticut 06520-8499, United States
| | - Federica Maschietto
- Department
of Chemistry, Yale University, New Haven, Connecticut 06520-8499, United States
| | - Elias Lolis
- Department
of Pharmacology, Yale University, New Haven, Connecticut 06520-8066, United States
| | - William H. Konigsberg
- Department
of Molecular Biophysics and Biochemistry, Yale University, New Haven, Connecticut 06520-8114, United States
| | - George P. Lisi
- Department
of Molecular and Cell Biology and Biochemistry, Brown University, Providence, Rhode Island 02912, United States
| | - Victor S. Batista
- Department
of Chemistry, Yale University, New Haven, Connecticut 06520-8499, United States
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6
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Abe K, Yamamoto K, Irie K, Nishizawa T, Oshima A. Gastric proton pump with two occluded K + engineered with sodium pump-mimetic mutations. Nat Commun 2021; 12:5709. [PMID: 34588453 PMCID: PMC8481561 DOI: 10.1038/s41467-021-26024-1] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2021] [Accepted: 09/10/2021] [Indexed: 12/13/2022] Open
Abstract
The gastric H+,K+-ATPase mediates electroneutral exchange of 1H+/1K+ per ATP hydrolysed across the membrane. Previous structural analysis of the K+-occluded E2-P transition state of H+,K+-ATPase showed a single bound K+ at cation-binding site II, in marked contrast to the two K+ ions occluded at sites I and II of the closely-related Na+,K+-ATPase which mediates electrogenic 3Na+/2K+ translocation across the membrane. The molecular basis of the different K+ stoichiometry between these K+-counter-transporting pumps is elusive. We show a series of crystal structures and a cryo-EM structure of H+,K+-ATPase mutants with changes in the vicinity of site I, based on the structure of the sodium pump. Our step-wise and tailored construction of the mutants finally gave a two-K+ bound H+,K+-ATPase, achieved by five mutations, including amino acids directly coordinating K+ (Lys791Ser, Glu820Asp), indirectly contributing to cation-binding site formation (Tyr340Asn, Glu936Val), and allosterically stabilizing K+-occluded conformation (Tyr799Trp). This quintuple mutant in the K+-occluded E2-P state unambiguously shows two separate densities at the cation-binding site in its 2.6 Å resolution cryo-EM structure. These results offer new insights into how two closely-related cation pumps specify the number of K+ accommodated at their cation-binding site. The gastric H+,K+-ATPase is a proton pump that creates the acidic environment of the stomach lumen, maintaining high proton gradient across the gastric mucosa cell membrane. Here, structural analysis of rationally designed H+,K+-ATPase mutants provides insight into this and other P-type ATPases cation binding stoichiometry and mechanisms.
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Affiliation(s)
- Kazuhiro Abe
- Cellular and Structural Physiology Institute, Nagoya University, Nagoya, 464-8601, Japan. .,Graduate School of Pharmaceutical Sciences, Nagoya University, Nagoya, 464-8601, Japan.
| | - Kenta Yamamoto
- Cellular and Structural Physiology Institute, Nagoya University, Nagoya, 464-8601, Japan.,Graduate School of Pharmaceutical Sciences, Nagoya University, Nagoya, 464-8601, Japan
| | - Katsumasa Irie
- Department of Biophysical Chemistry, Faculty of Pharmaceutical Sciences, Wakayama Medical University, 25-1 Shichibancho, Wakayama, 640-8156, Japan
| | - Tomohiro Nishizawa
- Graduate School of Medical Life Science, Yokohama City University, Tsurumi, Yokohama, 230-0045, Japan
| | - Atsunori Oshima
- Cellular and Structural Physiology Institute, Nagoya University, Nagoya, 464-8601, Japan.,Graduate School of Pharmaceutical Sciences, Nagoya University, Nagoya, 464-8601, Japan
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7
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Chan SI, Chang WH, Huang SH, Lin HH, Yu SSF. Catalytic machinery of methane oxidation in particulate methane monooxygenase (pMMO). J Inorg Biochem 2021; 225:111602. [PMID: 34547604 DOI: 10.1016/j.jinorgbio.2021.111602] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2021] [Revised: 08/21/2021] [Accepted: 09/09/2021] [Indexed: 10/20/2022]
Abstract
In this focused review, we portray the recently reported 2.5 Å cyro-EM structure of the particulate methane monooxygenase (pMMO) from M. capsulatus (Bath). The structure of the functional holo-pMMO near atomic resolution has uncovered the sites of the copper cofactors including the location of the active site in the enzyme. The three coppers seen in the original X-ray crystal structures of the enzyme are now augmented by additional coppers in the transmembrane domain as well as in the water-exposed C-terminal subdomain of the PmoB subunit. The cryo-EM structure offers the first glimpse of the catalytic machinery capable of methane oxidation with high selectivity and efficiency. The findings are entirely consistent with the biochemical and biophysical findings previously reported in the literature, including the chemistry of hydrocarbon hydroxylation, regeneration of the catalyst for multiple turnovers, and the mechanism of aborting non-productive cycles to ensure kinetic competence.
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Affiliation(s)
- Sunney I Chan
- Institute of Chemistry, Academia Sinica, Nankang, Taipei 11529, Taiwan.
| | - Wei-Hau Chang
- Institute of Chemistry, Academia Sinica, Nankang, Taipei 11529, Taiwan.
| | - Shih-Hsin Huang
- Institute of Chemistry, Academia Sinica, Nankang, Taipei 11529, Taiwan
| | - Hsin-Hung Lin
- Institute of Chemistry, Academia Sinica, Nankang, Taipei 11529, Taiwan
| | - Steve S-F Yu
- Institute of Chemistry, Academia Sinica, Nankang, Taipei 11529, Taiwan.
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8
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Chang WH, Lin HH, Tsai IK, Huang SH, Chung SC, Tu IP, Yu SSF, Chan SI. Copper Centers in the Cryo-EM Structure of Particulate Methane Monooxygenase Reveal the Catalytic Machinery of Methane Oxidation. J Am Chem Soc 2021; 143:9922-9932. [PMID: 34170126 DOI: 10.1021/jacs.1c04082] [Citation(s) in RCA: 31] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
The particulate methane monooxygenase (pMMO) is the first enzyme in the C1 metabolic pathway in methanotrophic bacteria. As this enzyme converts methane into methanol efficiently near room temperature, it has become the paradigm for developing an understanding of this difficult C1 chemistry. pMMO is a membrane-bound protein with three subunits (PmoB, PmoA, and PmoC) and 12-14 coppers distributed among different sites. X-ray crystal structures that have revealed only three mononuclear coppers at three sites have neither disclosed the location of the active site nor the catalytic mechanism of the enzyme. Here we report a cyro-EM structure of holo-pMMO from Methylococcus capsulatus (Bath) at 2.5 Å, and develop quantitative electrostatic-potential profiling to scrutinize the nonprotein densities for signatures of the copper cofactors. Our results confirm a mononuclear CuI at the A site, resolve two CuIs at the B site, and uncover additional CuI clusters at the PmoA/PmoC interface within the membrane (D site) and in the water-exposed C-terminal subdomain of the PmoB (E clusters). These findings complete the minimal set of copper factors required for catalytic turnover of pMMO, offering a glimpse of the catalytic machinery for methane oxidation according to the chemical principles underlying the mechanism proposed earlier.
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Affiliation(s)
- W-H Chang
- Institute of Chemistry, Academia Sinica, Nangang, Taipei 11529, Taiwan
| | - H-H Lin
- Institute of Chemistry, Academia Sinica, Nangang, Taipei 11529, Taiwan
| | - I-K Tsai
- Institute of Chemistry, Academia Sinica, Nangang, Taipei 11529, Taiwan
| | - S-H Huang
- Institute of Chemistry, Academia Sinica, Nangang, Taipei 11529, Taiwan
| | - S-C Chung
- Institute of Statistical Science, Academia Sinica, Nangang, Taipei 11529, Taiwan
| | - I-P Tu
- Institute of Statistical Science, Academia Sinica, Nangang, Taipei 11529, Taiwan
| | - S S-F Yu
- Institute of Chemistry, Academia Sinica, Nangang, Taipei 11529, Taiwan
| | - S I Chan
- Institute of Chemistry, Academia Sinica, Nangang, Taipei 11529, Taiwan
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9
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Torabi SF, Chen YL, Zhang K, Wang J, DeGregorio SJ, Vaidya AT, Su Z, Pabit SA, Chiu W, Pollack L, Steitz JA. Structural analyses of an RNA stability element interacting with poly(A). Proc Natl Acad Sci U S A 2021; 118:e2026656118. [PMID: 33785601 PMCID: PMC8040590 DOI: 10.1073/pnas.2026656118] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Cis-acting RNA elements are crucial for the regulation of polyadenylated RNA stability. The element for nuclear expression (ENE) contains a U-rich internal loop flanked by short helices. An ENE stabilizes RNA by sequestering the poly(A) tail via formation of a triplex structure that inhibits a rapid deadenylation-dependent decay pathway. Structure-based bioinformatic studies identified numerous ENE-like elements in evolutionarily diverse genomes, including a subclass containing two ENE motifs separated by a short double-helical region (double ENEs [dENEs]). Here, the structure of a dENE derived from a rice transposable element (TWIFB1) before and after poly(A) binding (∼24 kDa and ∼33 kDa, respectively) is investigated. We combine biochemical structure probing, small angle X-ray scattering (SAXS), and cryo-electron microscopy (cryo-EM) to investigate the dENE structure and its local and global structural changes upon poly(A) binding. Our data reveal 1) the directionality of poly(A) binding to the dENE, and 2) that the dENE-poly(A) interaction involves a motif that protects the 3'-most seven adenylates of the poly(A). Furthermore, we demonstrate that the dENE does not undergo a dramatic global conformational change upon poly(A) binding. These findings are consistent with the recently solved crystal structure of a dENE+poly(A) complex [S.-F. Torabi et al., Science 371, eabe6523 (2021)]. Identification of additional modes of poly(A)-RNA interaction opens new venues for better understanding of poly(A) tail biology.
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Affiliation(s)
- Seyed-Fakhreddin Torabi
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT 06536
- HHMI, Yale University School of Medicine, New Haven, CT 06536
| | - Yen-Lin Chen
- School of Applied and Engineering Physics, Cornell University, Ithaca, NY 14853
| | - Kaiming Zhang
- Department of Bioengineering, Stanford University, Stanford, CA 94305
- James H. Clark Center, Stanford University, Stanford, CA 94305
| | - Jimin Wang
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT 06536
| | - Suzanne J DeGregorio
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT 06536
- HHMI, Yale University School of Medicine, New Haven, CT 06536
| | - Anand T Vaidya
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT 06536
- HHMI, Yale University School of Medicine, New Haven, CT 06536
- Tata Institute of Fundamental Research Centre for Interdisciplinary Sciences, Tata Institute of Fundamental Research, 10 500046 Hyderabad, India
| | - Zhaoming Su
- Department of Bioengineering, Stanford University, Stanford, CA 94305
- James H. Clark Center, Stanford University, Stanford, CA 94305
| | - Suzette A Pabit
- School of Applied and Engineering Physics, Cornell University, Ithaca, NY 14853
| | - Wah Chiu
- Department of Bioengineering, Stanford University, Stanford, CA 94305;
- James H. Clark Center, Stanford University, Stanford, CA 94305
- Division of CryoEM and Bioimaging, Stanford Synchrotron Radiation Lightsource, Stanford Linear Accelerator Center National Accelerator Laboratory, Stanford University, Menlo Park, CA 94025
| | - Lois Pollack
- School of Applied and Engineering Physics, Cornell University, Ithaca, NY 14853;
| | - Joan A Steitz
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT 06536;
- HHMI, Yale University School of Medicine, New Haven, CT 06536
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10
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Wang J, Natchiar SK, Moore PB, Klaholz BP. Identification of Mg 2+ ions next to nucleotides in cryo-EM maps using electrostatic potential maps. Acta Crystallogr D Struct Biol 2021; 77:534-539. [PMID: 33825713 PMCID: PMC8025889 DOI: 10.1107/s2059798321001893] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2020] [Accepted: 02/16/2021] [Indexed: 11/10/2022] Open
Abstract
Cryo electron microscopy (cryo-EM) can produce maps of macromolecules that have resolutions that are sufficiently high that structural details such as chemical modifications, water molecules and bound metal ions can be discerned. However, those accustomed to interpreting the electron-density maps of macromolecules produced by X-ray crystallography need to be careful when assigning features such as these in cryo-EM maps because cations, for example, interact far more strongly with electrons than they do with X-rays. Using simulated electrostatic potential (ESP) maps as a tool led us to re-examine a recent cryo-EM map of the human ribosome, and we realized that some of the ESP peaks originally identified as novel groups covalently bonded to the N7, O6 or O4 atoms of several guanines, adenines or uridines, respectively, in this structure are likely to instead represent Mg2+ ions coordinated to these atoms, which provide only partial charge compensation compared with Mg2+ ions located next to phosphate groups. In addition, direct evidence is provided for a variation in the level of 2'-O ribose methylation of nucleotides in the human ribosome. ESP maps can thus help in identifying ions next to nucleotide bases, i.e. at positions that can be difficult to address in cryo-EM maps due to charge effects, which are specifically encountered in cryo-EM. This work is particularly relevant to nucleoprotein complexes and shows that it is important to consider charge effects when interpreting cryo-EM maps, thus opening possibilities for localizing charges in structures that may be relevant for enzymatic mechanisms and drug interactions.
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Affiliation(s)
- Jimin Wang
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT 06520-8114, USA
| | - S. Kundhavai Natchiar
- Centre for Integrative Biology (CBI), Department of Integrated Structural Biology, IGBMC, CNRS, Inserm, Université de Strasbourg, 1 Rue Laurent Fries, 67404 Illkirch, France
- Institute of Genetics and of Molecular and Cellular Biology (IGBMC), 1 Rue Laurent Fries, Illkirch, France
- Centre National de la Recherche Scientifique (CNRS), UMR 7104, Illkirch, France
- Institut National de la Santé et de la Recherche Médicale (Inserm), U964, Illkirch, France
- Université de Strasbourg, Illkirch, France
| | - Peter B. Moore
- Department of Chemistry, Yale University, New Haven, CT 06520-8107, USA
| | - Bruno P. Klaholz
- Centre for Integrative Biology (CBI), Department of Integrated Structural Biology, IGBMC, CNRS, Inserm, Université de Strasbourg, 1 Rue Laurent Fries, 67404 Illkirch, France
- Institute of Genetics and of Molecular and Cellular Biology (IGBMC), 1 Rue Laurent Fries, Illkirch, France
- Centre National de la Recherche Scientifique (CNRS), UMR 7104, Illkirch, France
- Institut National de la Santé et de la Recherche Médicale (Inserm), U964, Illkirch, France
- Université de Strasbourg, Illkirch, France
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11
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Birch J, Cheruvara H, Gamage N, Harrison PJ, Lithgo R, Quigley A. Changes in Membrane Protein Structural Biology. BIOLOGY 2020; 9:E401. [PMID: 33207666 PMCID: PMC7696871 DOI: 10.3390/biology9110401] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/14/2020] [Revised: 11/11/2020] [Accepted: 11/12/2020] [Indexed: 12/21/2022]
Abstract
Membrane proteins are essential components of many biochemical processes and are important pharmaceutical targets. Membrane protein structural biology provides the molecular rationale for these biochemical process as well as being a highly useful tool for drug discovery. Unfortunately, membrane protein structural biology is a difficult area of study due to low protein yields and high levels of instability especially when membrane proteins are removed from their native environments. Despite this instability, membrane protein structural biology has made great leaps over the last fifteen years. Today, the landscape is almost unrecognisable. The numbers of available atomic resolution structures have increased 10-fold though advances in crystallography and more recently by cryo-electron microscopy. These advances in structural biology were achieved through the efforts of many researchers around the world as well as initiatives such as the Membrane Protein Laboratory (MPL) at Diamond Light Source. The MPL has helped, provided access to and contributed to advances in protein production, sample preparation and data collection. Together, these advances have enabled higher resolution structures, from less material, at a greater rate, from a more diverse range of membrane protein targets. Despite this success, significant challenges remain. Here, we review the progress made and highlight current and future challenges that will be overcome.
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Affiliation(s)
- James Birch
- Membrane Protein Laboratory, Diamond Light Source Ltd., Harwell Science and Innovation Campus, Didcot OX11 0DE, UK; (J.B.); (H.C.); (N.G.); (P.J.H.); (R.L.)
- Research Complex at Harwell (RCaH), Harwell Science and Innovation Campus, Didcot OX11 0FA, UK
| | - Harish Cheruvara
- Membrane Protein Laboratory, Diamond Light Source Ltd., Harwell Science and Innovation Campus, Didcot OX11 0DE, UK; (J.B.); (H.C.); (N.G.); (P.J.H.); (R.L.)
- Research Complex at Harwell (RCaH), Harwell Science and Innovation Campus, Didcot OX11 0FA, UK
| | - Nadisha Gamage
- Membrane Protein Laboratory, Diamond Light Source Ltd., Harwell Science and Innovation Campus, Didcot OX11 0DE, UK; (J.B.); (H.C.); (N.G.); (P.J.H.); (R.L.)
- Research Complex at Harwell (RCaH), Harwell Science and Innovation Campus, Didcot OX11 0FA, UK
| | - Peter J. Harrison
- Membrane Protein Laboratory, Diamond Light Source Ltd., Harwell Science and Innovation Campus, Didcot OX11 0DE, UK; (J.B.); (H.C.); (N.G.); (P.J.H.); (R.L.)
- Research Complex at Harwell (RCaH), Harwell Science and Innovation Campus, Didcot OX11 0FA, UK
| | - Ryan Lithgo
- Membrane Protein Laboratory, Diamond Light Source Ltd., Harwell Science and Innovation Campus, Didcot OX11 0DE, UK; (J.B.); (H.C.); (N.G.); (P.J.H.); (R.L.)
- Research Complex at Harwell (RCaH), Harwell Science and Innovation Campus, Didcot OX11 0FA, UK
- School of Biosciences, University of Nottingham, Sutton Bonington Campus, Loughborough LE12 5RD, Leicestershire, UK
| | - Andrew Quigley
- Membrane Protein Laboratory, Diamond Light Source Ltd., Harwell Science and Innovation Campus, Didcot OX11 0DE, UK; (J.B.); (H.C.); (N.G.); (P.J.H.); (R.L.)
- Research Complex at Harwell (RCaH), Harwell Science and Innovation Campus, Didcot OX11 0FA, UK
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12
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Wang J, Perez-Cruet JM, Huang HL, Reiss K, Gisriel CJ, Banerjee G, Kaur D, Ghosh I, Dziarski A, Gunner MR, Batista VS, Brudvig GW. Identification of a Na +-Binding Site near the Oxygen-Evolving Complex of Spinach Photosystem II. Biochemistry 2020; 59:2823-2831. [PMID: 32650633 DOI: 10.1021/acs.biochem.0c00303] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The oxygen-evolving complex (OEC) of photosystem II (PSII) is an oxomanganese cluster composed of four redox-active Mn ions and one redox-inactive Ca2+ ion, with two nearby bound Cl- ions. Sodium is a common counterion of both chloride and hydroxide anions, and a sodium-specific binding site has not been identified near the OEC. Here, we find that the oxygen-evolution activity of spinach PSII increases with Na+ concentration, particularly at high pH. A Na+-specific binding site next to the OEC, becomes available after deprotonation of the D1-H337 amino acid residue, is suggested by the analysis of two recently published PSII cryo-electron microscopy maps in combination with quantum mechanical calculations and multiconformation continuum electrostatics simulations.
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Affiliation(s)
- Jimin Wang
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, Connecticut 06520-8114, United States
| | - Joshua M Perez-Cruet
- Department of Chemistry, Yale University, New Haven, Connecticut 06520-8107, United States
| | - Hao-Li Huang
- Department of Chemistry, Yale University, New Haven, Connecticut 06520-8107, United States
| | - Krystle Reiss
- Department of Chemistry, Yale University, New Haven, Connecticut 06520-8107, United States
| | - Christopher J Gisriel
- Department of Chemistry, Yale University, New Haven, Connecticut 06520-8107, United States
| | - Gourab Banerjee
- Department of Chemistry, Yale University, New Haven, Connecticut 06520-8107, United States
| | - Divya Kaur
- Department of Physics, City College of New York (CCNY), New York, New York 10031, United States.,Department of Chemistry, The Graduate Center of the City University of New York, New York, New York 10016, United States
| | - Ipsita Ghosh
- Department of Chemistry, Yale University, New Haven, Connecticut 06520-8107, United States
| | - Alisha Dziarski
- Department of Chemistry, Yale University, New Haven, Connecticut 06520-8107, United States
| | - M R Gunner
- Department of Physics, City College of New York (CCNY), New York, New York 10031, United States.,Department of Chemistry, The Graduate Center of the City University of New York, New York, New York 10016, United States
| | - Victor S Batista
- Department of Chemistry, Yale University, New Haven, Connecticut 06520-8107, United States
| | - Gary W Brudvig
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, Connecticut 06520-8114, United States.,Department of Chemistry, Yale University, New Haven, Connecticut 06520-8107, United States
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13
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Radon C, Mittelstädt G, Duffus BR, Bürger J, Hartmann T, Mielke T, Teutloff C, Leimkühler S, Wendler P. Cryo-EM structures reveal intricate Fe-S cluster arrangement and charging in Rhodobacter capsulatus formate dehydrogenase. Nat Commun 2020; 11:1912. [PMID: 32313256 PMCID: PMC7171172 DOI: 10.1038/s41467-020-15614-0] [Citation(s) in RCA: 39] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2019] [Accepted: 03/19/2020] [Indexed: 11/09/2022] Open
Abstract
Metal-containing formate dehydrogenases (FDH) catalyse the reversible oxidation of formate to carbon dioxide at their molybdenum or tungsten active site. They display a diverse subunit and cofactor composition, but structural information on these enzymes is limited. Here we report the cryo-electron microscopic structures of the soluble Rhodobacter capsulatus FDH (RcFDH) as isolated and in the presence of reduced nicotinamide adenine dinucleotide (NADH). RcFDH assembles into a 360 kDa dimer of heterotetramers revealing a putative interconnection of electron pathway chains. In the presence of NADH, the RcFDH structure shows charging of cofactors, indicative of an increased electron load. Rhodobacter capsulatus NAD+ dependent formate dehydrogenase (RcFDH) is a molybdoenzyme that catalyses the reversible oxidation of formate to carbon dioxide, and is of interest for biotechnological applications. Here the authors present the cryo-EM structures of RcFDH as isolated from R. capsulatus and in the reduced state with bound NADH, and discuss the enzyme mechanism.
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Affiliation(s)
- Christin Radon
- Institute of Biochemistry and Biology, Department of Biochemistry, University of Potsdam, Karl-Liebknecht Strasse 24-25, 14476, Potsdam-Golm, Germany
| | - Gerd Mittelstädt
- Institute of Biochemistry and Biology, Department of Molecular Enzymology, University of Potsdam, Karl-Liebknecht Strasse 24-25, 14476, Potsdam-Golm, Germany.,Ferrier Research Institute, Victoria University of Wellington, Kelburn Parade, Wellington, 6012, New Zealand
| | - Benjamin R Duffus
- Institute of Biochemistry and Biology, Department of Molecular Enzymology, University of Potsdam, Karl-Liebknecht Strasse 24-25, 14476, Potsdam-Golm, Germany
| | - Jörg Bürger
- Max-Planck Institute of Molecular Genetics, Ihnestrasse 63-73, 14195, Berlin, Germany.,Charité, Institut für Medizinische Physik und Biophysik, Charitéplatz 1, 10117, Berlin, Germany
| | - Tobias Hartmann
- Institute of Biochemistry and Biology, Department of Molecular Enzymology, University of Potsdam, Karl-Liebknecht Strasse 24-25, 14476, Potsdam-Golm, Germany
| | - Thorsten Mielke
- Max-Planck Institute of Molecular Genetics, Ihnestrasse 63-73, 14195, Berlin, Germany
| | - Christian Teutloff
- Department of Physics, Freie Universität Berlin, Arnimallee 14, 14195, Berlin, Germany
| | - Silke Leimkühler
- Institute of Biochemistry and Biology, Department of Molecular Enzymology, University of Potsdam, Karl-Liebknecht Strasse 24-25, 14476, Potsdam-Golm, Germany
| | - Petra Wendler
- Institute of Biochemistry and Biology, Department of Biochemistry, University of Potsdam, Karl-Liebknecht Strasse 24-25, 14476, Potsdam-Golm, Germany.
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14
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Nannenga BL. MicroED methodology and development. STRUCTURAL DYNAMICS (MELVILLE, N.Y.) 2020; 7:014304. [PMID: 32071929 PMCID: PMC7018523 DOI: 10.1063/1.5128226] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/19/2019] [Accepted: 01/24/2020] [Indexed: 06/10/2023]
Abstract
Microcrystal electron diffraction, or MicroED, is a method that is capable of determining structure from very small and thin 3D crystals using a transmission electron microscope. MicroED has been successfully used on microcrystalline samples, including proteins, peptides, and small organic molecules, in many cases to very high resolutions. In this work, the MicroED workflow will be briefly described and areas of future method development will be highlighted. These areas include improvements in sample preparation, data collection, and structure determination.
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Affiliation(s)
- Brent L Nannenga
- Chemical Engineering, School for Engineering of Matter, Transport, and Energy, Arizona State University, Tempe, Arizona 85287, USA and Center for Applied Structural Discovery, The Biodesign Institute, Arizona State University, Tempe, Arizona 85281, USA
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15
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Kaledhonkar S, Fu Z, Caban K, Li W, Chen B, Sun M, Gonzalez RL, Frank J. Late steps in bacterial translation initiation visualized using time-resolved cryo-EM. Nature 2019; 570:400-404. [PMID: 31108498 PMCID: PMC7060745 DOI: 10.1038/s41586-019-1249-5] [Citation(s) in RCA: 79] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2018] [Accepted: 05/08/2019] [Indexed: 12/02/2022]
Abstract
The initiation of bacterial translation involves the tightly regulated joining of the 50S ribosomal subunit to an initiator transfer RNA (fMet-tRNAfMet)-containing 30S ribosomal initiation complex to form a 70S initiation complex, which subsequently matures into a 70S elongation-competent complex. Rapid and accurate formation of the 70S initiation complex is promoted by initiation factors, which must dissociate from the 30S initiation complex before the resulting 70S elongation-competent complex can begin the elongation of translation1. Although comparisons of the structures of the 30S2-5 and 70S4,6-8 initiation complexes have revealed that the ribosome, initiation factors and fMet-tRNAfMet can acquire different conformations in these complexes, the timing of conformational changes during formation of the 70S initiation complex, the structures of any intermediates formed during these rearrangements, and the contributions that these dynamics might make to the mechanism and regulation of initiation remain unknown. Moreover, the absence of a structure of the 70S elongation-competent complex formed via an initiation-factor-catalysed reaction has precluded an understanding of the rearrangements to the ribosome, initiation factors and fMet-tRNAfMet that occur during maturation of a 70S initiation complex into a 70S elongation-competent complex. Here, using time-resolved cryogenic electron microscopy9, we report the near-atomic-resolution view of how a time-ordered series of conformational changes drive and regulate subunit joining, initiation factor dissociation and fMet-tRNAfMet positioning during formation of the 70S elongation-competent complex. Our results demonstrate the power of time-resolved cryogenic electron microscopy to determine how a time-ordered series of conformational changes contribute to the mechanism and regulation of one of the most fundamental processes in biology.
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MESH Headings
- Cryoelectron Microscopy
- Escherichia coli/chemistry
- Escherichia coli/metabolism
- Escherichia coli/ultrastructure
- Peptide Chain Elongation, Translational
- Peptide Chain Initiation, Translational
- Protein Conformation
- Ribosome Subunits, Large, Bacterial/metabolism
- Ribosome Subunits, Large, Bacterial/ultrastructure
- Ribosome Subunits, Small, Bacterial/metabolism
- Ribosome Subunits, Small, Bacterial/ultrastructure
- Ribosomes/chemistry
- Ribosomes/metabolism
- Ribosomes/ultrastructure
- Time Factors
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Affiliation(s)
- Sandip Kaledhonkar
- Department of Biochemistry & Molecular Biophysics, Columbia University, New York, NY, USA
| | - Ziao Fu
- Integrated Program in Cellular, Molecular and Biophysical Studies, Columbia University, College of Physicians and Surgeons, New York, NY, USA
| | - Kelvin Caban
- Department of Chemistry, Columbia University, New York, NY, USA
| | - Wen Li
- Department of Biochemistry & Molecular Biophysics, Columbia University, New York, NY, USA
| | - Bo Chen
- Department of Biochemistry & Molecular Biophysics, Columbia University, New York, NY, USA
| | - Ming Sun
- Department of Biological Sciences, Columbia University, New York, NY, USA
| | - Ruben L Gonzalez
- Department of Chemistry, Columbia University, New York, NY, USA.
| | - Joachim Frank
- Department of Biochemistry & Molecular Biophysics, Columbia University, New York, NY, USA.
- Department of Biological Sciences, Columbia University, New York, NY, USA.
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16
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Cruz JC, Hernández-Esparza R, Vázquez-Mayagoitia Á, Vargas R, Garza J. Implementation of the Molecular Electrostatic Potential over Graphics Processing Units. J Chem Inf Model 2019; 59:3120-3127. [DOI: 10.1021/acs.jcim.8b00951] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- J. César Cruz
- Departamento de Química, División de Ciencias Básicas e Ingeniería, Universidad Autónoma Metropolitana-Iztapalapa, San Rafael Atlixco 186, Col. Vicentina, Iztapalapa. C. P. 09340, Ciudad de México, México
| | - Raymundo Hernández-Esparza
- Departamento de Química, División de Ciencias Básicas e Ingeniería, Universidad Autónoma Metropolitana-Iztapalapa, San Rafael Atlixco 186, Col. Vicentina, Iztapalapa. C. P. 09340, Ciudad de México, México
| | - Álvaro Vázquez-Mayagoitia
- Argonne Leadership Computing Facility, Argonne National Laboratory, 9700 S. Cass Avenue, Lemont, Illinois 60439, United States
| | - Rubicelia Vargas
- Departamento de Química, División de Ciencias Básicas e Ingeniería, Universidad Autónoma Metropolitana-Iztapalapa, San Rafael Atlixco 186, Col. Vicentina, Iztapalapa. C. P. 09340, Ciudad de México, México
| | - Jorge Garza
- Departamento de Química, División de Ciencias Básicas e Ingeniería, Universidad Autónoma Metropolitana-Iztapalapa, San Rafael Atlixco 186, Col. Vicentina, Iztapalapa. C. P. 09340, Ciudad de México, México
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17
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Wang J, Reiss K, Brudvig GW, Batista VS. Reduced Occupancy of the Oxygen-Evolving Complex of Photosystem II Detected in Cryo-Electron Microscopy Maps. Biochemistry 2018; 57:5925-5929. [PMID: 30260634 DOI: 10.1021/acs.biochem.8b00609] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Computational simulations of electrostatic potentials (ESPs), based on atomistic models and independent atomic scattering factors, have remained challenging when applied to the oxygen-evolving complex (OEC) of photosystem II (PSII). Here, we overcome that challenge by using an ESP function obtained with density functional theory and atomic coordinates for the OEC of PSII obtained by optimization of the dark-adapted S1 state. We find that the ESP is much higher for the OEC than for the nearby reference side chain of amino acid residue D1-H190. In contrast, experimental ESP maps recently published for two PSII-light-harvesting complex II super-complexes show that the ESP of the OEC is approximately half the value of the D1-H190 side chain. The apparent disparity is attributed to a reduced 31-38% occupancy of the OEC, likely associated with its reduction by electron scattering.
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Affiliation(s)
- Jimin Wang
- Department of Molecular Biophysics and Biochemistry , Yale University , New Haven , Connecticut 06520-8114 , United States
| | - Krystle Reiss
- Department of Chemistry , Yale University , New Haven , Connecticut 06520-8107 , United States
| | - Gary W Brudvig
- Department of Chemistry , Yale University , New Haven , Connecticut 06520-8107 , United States
| | - Victor S Batista
- Department of Chemistry , Yale University , New Haven , Connecticut 06520-8107 , United States
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