1
|
Márquez I, Pérez‐Mejías G, Guerra‐Castellano A, Olloqui‐Sariego JL, Andreu R, Calvente JJ, De la Rosa MA, Díaz‐Moreno I. Structural and functional insights into lysine acetylation of cytochrome c using mimetic point mutants. FEBS Open Bio 2021; 11:3304-3323. [PMID: 34455704 PMCID: PMC8634867 DOI: 10.1002/2211-5463.13284] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2021] [Revised: 08/24/2021] [Accepted: 08/27/2021] [Indexed: 11/29/2022] Open
Abstract
Post-translational modifications frequently modulate protein functions. Lysine acetylation in particular plays a key role in interactions between respiratory cytochrome c and its metabolic partners. To date, in vivo acetylation of lysines at positions 8 and 53 has specifically been identified in mammalian cytochrome c, but little is known about the structural basis of acetylation-induced functional changes. Here, we independently replaced these two residues in recombinant human cytochrome c with glutamine to mimic lysine acetylation and then characterized the structure and function of the resulting K8Q and K53Q mutants. We found that the physicochemical features were mostly unchanged in the two acetyl-mimetic mutants, but their thermal stability was significantly altered. NMR chemical shift perturbations of the backbone amide resonances revealed local structural changes, and the thermodynamics and kinetics of electron transfer in mutants immobilized on gold electrodes showed an increase in both protein dynamics and solvent involvement in the redox process. We also observed that the K8Q (but not the K53Q) mutation slightly increased the binding affinity of cytochrome c to its physiological electron donor, cytochrome c1 -which is a component of mitochondrial complex III, or cytochrome bc1 -thus suggesting that Lys8 (but not Lys53) is located in the interaction area. Finally, the K8Q and K53Q mutants exhibited reduced efficiency as electron donors to complex IV, or cytochrome c oxidase.
Collapse
Affiliation(s)
- Inmaculada Márquez
- Institute for Chemical Research (IIQ)Scientific Research Centre Isla de la Cartuja (cicCartuja)University of Seville – CSICSpain
| | - Gonzalo Pérez‐Mejías
- Institute for Chemical Research (IIQ)Scientific Research Centre Isla de la Cartuja (cicCartuja)University of Seville – CSICSpain
| | - Alejandra Guerra‐Castellano
- Institute for Chemical Research (IIQ)Scientific Research Centre Isla de la Cartuja (cicCartuja)University of Seville – CSICSpain
| | | | - Rafael Andreu
- Departament of Physical ChemistryUniversity of SevilleSpain
| | | | - Miguel A. De la Rosa
- Institute for Chemical Research (IIQ)Scientific Research Centre Isla de la Cartuja (cicCartuja)University of Seville – CSICSpain
| | - Irene Díaz‐Moreno
- Institute for Chemical Research (IIQ)Scientific Research Centre Isla de la Cartuja (cicCartuja)University of Seville – CSICSpain
| |
Collapse
|
2
|
González‐Arzola K, Guerra‐Castellano A, Rivero‐Rodríguez F, Casado‐Combreras MÁ, Pérez‐Mejías G, Díaz‐Quintana A, Díaz‐Moreno I, De la Rosa MA. Mitochondrial cytochrome c shot towards histone chaperone condensates in the nucleus. FEBS Open Bio 2021; 11:2418-2440. [PMID: 33938164 PMCID: PMC8409293 DOI: 10.1002/2211-5463.13176] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2021] [Accepted: 04/26/2021] [Indexed: 12/15/2022] Open
Abstract
Despite mitochondria being key for the control of cell homeostasis and fate, their role in DNA damage response is usually just regarded as an apoptotic trigger. However, growing evidence points to mitochondrial factors modulating nuclear functions. Remarkably, after DNA damage, cytochrome c (Cc) interacts in the cell nucleus with a variety of well-known histone chaperones, whose activity is competitively inhibited by the haem protein. As nuclear Cc inhibits the nucleosome assembly/disassembly activity of histone chaperones, it might indeed affect chromatin dynamics and histone deposition on DNA. Several histone chaperones actually interact with Cc Lys residues through their acidic regions, which are also involved in heterotypic interactions leading to liquid-liquid phase transitions responsible for the assembly of nuclear condensates, including heterochromatin. This relies on dynamic histone-DNA interactions that can be modulated by acetylation of specific histone Lys residues. Thus, Cc may have a major regulatory role in DNA repair by fine-tuning nucleosome assembly activity and likely nuclear condensate formation.
Collapse
Affiliation(s)
- Katiuska González‐Arzola
- Institute for Chemical Research (IIQ)Scientific Research Centre Isla de la Cartuja (cicCartuja)University of Seville – CSICSpain
| | - Alejandra Guerra‐Castellano
- Institute for Chemical Research (IIQ)Scientific Research Centre Isla de la Cartuja (cicCartuja)University of Seville – CSICSpain
| | - Francisco Rivero‐Rodríguez
- Institute for Chemical Research (IIQ)Scientific Research Centre Isla de la Cartuja (cicCartuja)University of Seville – CSICSpain
| | - Miguel Á. Casado‐Combreras
- Institute for Chemical Research (IIQ)Scientific Research Centre Isla de la Cartuja (cicCartuja)University of Seville – CSICSpain
| | - Gonzalo Pérez‐Mejías
- Institute for Chemical Research (IIQ)Scientific Research Centre Isla de la Cartuja (cicCartuja)University of Seville – CSICSpain
| | - Antonio Díaz‐Quintana
- Institute for Chemical Research (IIQ)Scientific Research Centre Isla de la Cartuja (cicCartuja)University of Seville – CSICSpain
| | - Irene Díaz‐Moreno
- Institute for Chemical Research (IIQ)Scientific Research Centre Isla de la Cartuja (cicCartuja)University of Seville – CSICSpain
| | - Miguel A. De la Rosa
- Institute for Chemical Research (IIQ)Scientific Research Centre Isla de la Cartuja (cicCartuja)University of Seville – CSICSpain
| |
Collapse
|
3
|
Elena-Real CA, González-Arzola K, Pérez-Mejías G, Díaz-Quintana A, Velázquez-Campoy A, Desvoyes B, Gutiérrez C, De la Rosa MA, Díaz-Moreno I. Proposed mechanism for regulation of H 2 O 2 -induced programmed cell death in plants by binding of cytochrome c to 14-3-3 proteins. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2021; 106:74-85. [PMID: 33354856 DOI: 10.1111/tpj.15146] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/02/2018] [Revised: 11/16/2020] [Accepted: 12/14/2020] [Indexed: 05/27/2023]
Abstract
Programmed cell death (PCD) is crucial for development and homeostasis of all multicellular organisms. In human cells, the double role of extra-mitochondrial cytochrome c in triggering apoptosis and inhibiting survival pathways is well reported. In plants, however, the specific role of cytochrome c upon release from the mitochondria remains in part veiled yet death stimuli do trigger cytochrome c translocation as well. Here, we identify an Arabidopsis thaliana 14-3-3ι isoform as a cytosolic cytochrome c target and inhibitor of caspase-like activity. This finding establishes the 14-3-3ι protein as a relevant factor at the onset of plant H2 O2 -induced PCD. The in vivo and in vitro studies herein reported reveal that the interaction between cytochrome c and 14-3-3ι exhibits noticeable similarities with the complex formed by their human orthologues. Further analysis of the heterologous complexes between human and plant cytochrome c with plant 14-3-3ι and human 14-3-3ε isoforms corroborated common features. These results suggest that cytochrome c blocks p14-3-3ι so as to inhibit caspase-like proteases, which in turn promote cell death upon H2 O2 treatment. Besides establishing common biochemical features between human and plant PCD, this work sheds light onto the signaling networks of plant cell death.
Collapse
Affiliation(s)
- Carlos A Elena-Real
- Instituto de Investigaciones Químicas (IIQ) e Instituto de Bioquímica Vegetal y Fotosíntesis (IBVF), Centro de Investigaciones Científicas Isla de la Cartuja (cicCartuja), Universidad de Sevilla - Consejo Superior de Investigaciones Científicas (CSIC), Avda. Americo Vespucio 49, Sevilla, 41092, Spain
| | - Katiuska González-Arzola
- Instituto de Investigaciones Químicas (IIQ) e Instituto de Bioquímica Vegetal y Fotosíntesis (IBVF), Centro de Investigaciones Científicas Isla de la Cartuja (cicCartuja), Universidad de Sevilla - Consejo Superior de Investigaciones Científicas (CSIC), Avda. Americo Vespucio 49, Sevilla, 41092, Spain
| | - Gonzalo Pérez-Mejías
- Instituto de Investigaciones Químicas (IIQ) e Instituto de Bioquímica Vegetal y Fotosíntesis (IBVF), Centro de Investigaciones Científicas Isla de la Cartuja (cicCartuja), Universidad de Sevilla - Consejo Superior de Investigaciones Científicas (CSIC), Avda. Americo Vespucio 49, Sevilla, 41092, Spain
| | - Antonio Díaz-Quintana
- Instituto de Investigaciones Químicas (IIQ) e Instituto de Bioquímica Vegetal y Fotosíntesis (IBVF), Centro de Investigaciones Científicas Isla de la Cartuja (cicCartuja), Universidad de Sevilla - Consejo Superior de Investigaciones Científicas (CSIC), Avda. Americo Vespucio 49, Sevilla, 41092, Spain
| | - Adrián Velázquez-Campoy
- Institute of Biocomputation and Physics of Complex Systems (BIFI), Joint Units IQFR-CSIC-BIFI, and GBsC-CSIC-BIFI, Universidad de Zaragoza, Zaragoza, 50018, Spain
- Department of Biochemistry and Molecular and Cell Biology, Universidad de Zaragoza, Zaragoza, 50009, Spain
- Aragon Institute for Health Research (IIS Aragon), Zaragoza, 50009, Spain
- Biomedical Research Networking Centre for Liver and Digestive Diseases (CIBERehd), Madrid, 28029, Spain
- Fundacion ARAID, Government of Aragon, Zaragoza, 50018, Spain
| | - Bénédicte Desvoyes
- Centro de Biología Molecular Severo Ochoa, CSIC-UAM, Nicolás Cabrera 1, Cantoblanco, Madrid, 28049, Spain
| | - Crisanto Gutiérrez
- Centro de Biología Molecular Severo Ochoa, CSIC-UAM, Nicolás Cabrera 1, Cantoblanco, Madrid, 28049, Spain
| | - Miguel A De la Rosa
- Instituto de Investigaciones Químicas (IIQ) e Instituto de Bioquímica Vegetal y Fotosíntesis (IBVF), Centro de Investigaciones Científicas Isla de la Cartuja (cicCartuja), Universidad de Sevilla - Consejo Superior de Investigaciones Científicas (CSIC), Avda. Americo Vespucio 49, Sevilla, 41092, Spain
| | - Irene Díaz-Moreno
- Instituto de Investigaciones Químicas (IIQ) e Instituto de Bioquímica Vegetal y Fotosíntesis (IBVF), Centro de Investigaciones Científicas Isla de la Cartuja (cicCartuja), Universidad de Sevilla - Consejo Superior de Investigaciones Científicas (CSIC), Avda. Americo Vespucio 49, Sevilla, 41092, Spain
| |
Collapse
|
4
|
Guerra-Castellano A, Márquez I, Pérez-Mejías G, Díaz-Quintana A, De la Rosa MA, Díaz-Moreno I. Post-Translational Modifications of Cytochrome c in Cell Life and Disease. Int J Mol Sci 2020; 21:E8483. [PMID: 33187249 PMCID: PMC7697256 DOI: 10.3390/ijms21228483] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2020] [Revised: 11/05/2020] [Accepted: 11/07/2020] [Indexed: 02/07/2023] Open
Abstract
Mitochondria are the powerhouses of the cell, whilst their malfunction is related to several human pathologies, including neurodegenerative diseases, cardiovascular diseases, and various types of cancer. In mitochondrial metabolism, cytochrome c is a small soluble heme protein that acts as an essential redox carrier in the respiratory electron transport chain. However, cytochrome c is likewise an essential protein in the cytoplasm acting as an activator of programmed cell death. Such a dual role of cytochrome c in cell life and death is indeed fine-regulated by a wide variety of protein post-translational modifications. In this work, we show how these modifications can alter cytochrome c structure and functionality, thus emerging as a control mechanism of cell metabolism but also as a key element in development and prevention of pathologies.
Collapse
Affiliation(s)
| | | | | | | | | | - Irene Díaz-Moreno
- Instituto de Investigaciones Químicas (IIQ), Centro de Investigaciones Científicas Isla de la Cartuja (cicCartuja), Universidad de Sevilla, Consejo Superior de Investigaciones Científicas (CSIC), Avda. Américo Vespucio 49, 41092 Sevilla, Spain; (A.G.-C.); (I.M.); (G.P.-M.); (A.D.-Q.); (M.A.D.l.R.)
| |
Collapse
|
5
|
Olloqui-Sariego JL, Márquez I, Frutos-Beltrán E, Díaz-Moreno I, De la Rosa MA, Calvente JJ, Andreu R, Díaz-Quintana A. Key Role of the Local Hydrophobicity in the East Patch of Plastocyanins on Their Thermal Stability and Redox Properties. ACS OMEGA 2018; 3:11447-11454. [PMID: 31459248 PMCID: PMC6645426 DOI: 10.1021/acsomega.8b01612] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/11/2018] [Accepted: 09/06/2018] [Indexed: 06/10/2023]
Abstract
Understanding the molecular basis of the thermal stability and functionality of redox proteins has important practical applications. Here, we show a distinct thermal dependence of the spectroscopic and electrochemical properties of two plastocyanins from the thermophilic cyanobacterium Phormidium laminosum and their mesophilic counterpart from Synechocystis sp. PCC 6803, despite the similarity of their molecular structures. To explore the origin of these differences, we have mimicked the local hydrophobicity in the east patch of the thermophilic protein by replacing a valine of the mesophilic plastocyanin by isoleucine. Interestingly, the resulting mutant approaches the thermal stability, redox thermodynamics, and dynamic coupling of the flexible site motions of the thermophilic protein, indicating the existence of a close connection between the hydrophobic packing of the east patch region of plastocyanin and the functional control and stability of the oxidized and reduced forms of the protein.
Collapse
Affiliation(s)
- José Luis Olloqui-Sariego
- Departamento
de Química Física, Universidad
de Sevilla, c/ Profesor García González, 1, 41012 Sevilla, Spain
| | - Inmaculada Márquez
- Departamento
de Química Física, Universidad
de Sevilla, c/ Profesor García González, 1, 41012 Sevilla, Spain
| | - Estrella Frutos-Beltrán
- Instituto
de Investigaciones Químicas, cicCartuja, Universidad de Sevilla y CSIC, Avd. Américo Vespucio 49, 41092 Sevilla, Spain
| | - Irene Díaz-Moreno
- Instituto
de Investigaciones Químicas, cicCartuja, Universidad de Sevilla y CSIC, Avd. Américo Vespucio 49, 41092 Sevilla, Spain
| | - Miguel A. De la Rosa
- Instituto
de Investigaciones Químicas, cicCartuja, Universidad de Sevilla y CSIC, Avd. Américo Vespucio 49, 41092 Sevilla, Spain
| | - Juan José Calvente
- Departamento
de Química Física, Universidad
de Sevilla, c/ Profesor García González, 1, 41012 Sevilla, Spain
| | - Rafael Andreu
- Departamento
de Química Física, Universidad
de Sevilla, c/ Profesor García González, 1, 41012 Sevilla, Spain
| | - Antonio Díaz-Quintana
- Instituto
de Investigaciones Químicas, cicCartuja, Universidad de Sevilla y CSIC, Avd. Américo Vespucio 49, 41092 Sevilla, Spain
| |
Collapse
|
6
|
The dynamic complex of cytochrome c6 and cytochrome f studied with paramagnetic NMR spectroscopy. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2014; 1837:1305-15. [DOI: 10.1016/j.bbabio.2014.03.009] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/27/2014] [Revised: 03/13/2014] [Accepted: 03/16/2014] [Indexed: 11/23/2022]
|
7
|
Molecular basis of active copper resistance mechanisms in Gram-negative bacteria. Cell Biol Toxicol 2013; 29:397-405. [PMID: 24072389 PMCID: PMC3847284 DOI: 10.1007/s10565-013-9262-1] [Citation(s) in RCA: 118] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2013] [Accepted: 09/16/2013] [Indexed: 10/26/2022]
Abstract
Copper is a metallic element that is crucial for cell metabolism; however, in extended concentrations, it is toxic for all living organisms. The dual nature of copper has forced organisms, including bacteria, to keep a tight hold on cellular copper content. This challenge has led to the evolution of complex mechanisms that on one hand enable them to deliver the essential element and on the other to protect cells against its toxicity. Such mechanisms have been found in both eukaryotic and prokaryotic cells. In bacteria a number of different systems such as extra- and intracellular sequestration, enzymatic detoxification, and metal removal from the cell enabling them to survive in the presence of high concentration of copper have been identified. Gram-negative bacteria, due to their additional compartment, need to deal with both cytoplasmic and periplasmic copper. Therefore, these bacteria have evolved intricate and precisely regulated systems which interact with each other. In this review the active mechanisms of copper resistance at their molecular level are discussed.
Collapse
|
8
|
Kovalenko IB, Knyazeva OS, Riznichenko GY, Rubin AB. Mechanisms of interaction of electron transport proteins in photosynthetic membranes of cyanobacteria. DOKL BIOCHEM BIOPHYS 2011; 440:213-5. [PMID: 22095121 DOI: 10.1134/s160767291105005x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2011] [Indexed: 11/22/2022]
Affiliation(s)
- I B Kovalenko
- Faculty of Biology, Moscow State University, Moscow, Russia
| | | | | | | |
Collapse
|
9
|
Xu W, Wang Y, Taylor E, Laujac A, Gao L, Savikhin S, Chitnis PR. Mutational analysis of photosystem I of Synechocystis sp. PCC 6803: the role of four conserved aromatic residues in the j-helix of PsaB. PLoS One 2011; 6:e24625. [PMID: 21931782 PMCID: PMC3171458 DOI: 10.1371/journal.pone.0024625] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2011] [Accepted: 08/15/2011] [Indexed: 11/19/2022] Open
Abstract
Photosystem I is the light-driven plastocyanin-ferredoxin oxidoreductase in the photosynthetic electron transfer of cyanobacteria and plants. Two histidyl residues in the symmetric transmembrane helices A-j and B-j provide ligands for the P700 chlorophyll molecules of the reaction center of photosystem I. To determine the role of conserved aromatic residues adjacent to the histidyl molecule in the helix of B-j, we generated six site-directed mutants of the psaB gene in Synechocystis sp. PCC 6803. Three mutant strains with W645C, W643C/A644I and S641C/V642I substitutions could grow photoautotrophically and showed no obvious reduction in the photosystem I activity. Kinetics of P700 re-reduction by plastocyanin remained unaltered in these mutants. In contrast, the strains with H651C/L652M, F649C/G650I and F647C substitutions could not grow under photoautotrophic conditions because those mutants had low photosystem I activity, possibly due to low levels of proteins. A procedure to select spontaneous revertants from the mutants that are incapable to photoautotrophic growth resulted in three revertants that were used in this study. The molecular analysis of the spontaneous revertants suggested that an aromatic residue at F647 and a small residue at G650 may be necessary for maintaining the structural integrity of photosystem I. The (P700⁺-P700) steady-state absorption difference spectrum of the revertant F647Y has a ∼5 nm narrower peak than the recovered wild-type, suggesting that additional hydroxyl group of this revertant may participate in the interaction with the special pair while the photosystem I complexes of the F649C/G650T and H651Q mutants closely resemble the wild-type spectrum. The results presented here demonstrate that the highly conserved residues W645, W643 and F649 are not critical for maintaining the integrity and in mediating electron transport from plastocyanin to photosystem I. Our data suggest that an aromatic residue is required at position of 647 for structural integrity and/or function of photosystem I.
Collapse
Affiliation(s)
- Wu Xu
- Department of Chemistry, University of Louisiana at Lafayette, Lafayette, Louisiana, United States of America
| | - Yingchun Wang
- Key Laboratory of Molecular and Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Science, Beijing, China
| | - Eric Taylor
- Department of Chemistry, University of Louisiana at Lafayette, Lafayette, Louisiana, United States of America
| | - Amelie Laujac
- Department of Chemistry, University of Louisiana at Lafayette, Lafayette, Louisiana, United States of America
| | - Liyan Gao
- Key Laboratory of Molecular and Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Science, Beijing, China
| | - Sergei Savikhin
- Department of Physics, Purdue University, West Lafayette, Indiana, United States of America
| | - Parag R. Chitnis
- Department of Biochemistry, Biophysics and Molecular Biology, Iowa State University, Ames, Iowa, United States of America
| |
Collapse
|
10
|
Cruz-Gallardo I, Díaz-Moreno I, Díaz-Quintana A, De la Rosa MA. The cytochrome f
-plastocyanin complex as a model to study transient interactions between redox proteins. FEBS Lett 2011; 586:646-52. [DOI: 10.1016/j.febslet.2011.08.035] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2011] [Revised: 08/08/2011] [Accepted: 08/24/2011] [Indexed: 01/23/2023]
|
11
|
Nakamura A, Suzawa T, Kato Y, Watanabe T. Species Dependence of the Redox Potential of the Primary Electron Donor P700 in Photosystem I of Oxygenic Photosynthetic Organisms Revealed by Spectroelectrochemistry. ACTA ACUST UNITED AC 2011; 52:815-23. [DOI: 10.1093/pcp/pcr034] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
|
12
|
Purification of plastocyanin and cytochrome c6 from plants, green algae, and cyanobacteria. Methods Mol Biol 2011; 684:79-94. [PMID: 20960123 DOI: 10.1007/978-1-60761-925-3_8] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/30/2023]
Abstract
Plastocyanin and cytochrome c6 are widely distributed over the oxygen-evolving photosynthetic organisms. The two proteins are functionally equivalent, but strongly differ in their global electrostatic charge. In fact, they are acidic in eukaryotes, but either neutral or basic in cyanobacteria. Such a difference in their electrostatic features is a critical factor in designing the purification procedure, which must thus be modified and adapted accordingly. This chapter reports the methods for producing (including cell cultures), isolating, and purifying plastocyanin and cytochrome c6--which greatly differ in their isoelectric point--from a number of eukaryotic and prokaryotic organisms.
Collapse
|
13
|
Muñoz-López FJ, Beltrán EF, Díaz-Moreno S, Díaz-Moreno I, Subías G, De la Rosa MA, Díaz-Quintana A. Modulation of copper site properties by remote residues determines the stability of plastocyanins. FEBS Lett 2010; 584:2346-50. [PMID: 20398655 DOI: 10.1016/j.febslet.2010.04.013] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2009] [Revised: 04/07/2010] [Accepted: 04/07/2010] [Indexed: 11/18/2022]
Abstract
The metal cofactor determines the thermal stability in cupredoxins, but how the redox state of copper modulates their melting points remains unknown. The metal coordination environment is highly conserved in cyanobacterial plastocyanins. However, the oxidised form is more stable than the reduced one in thermophilic Phormidium, but the opposite occurs in mesophilic Synechocystis. We have performed neutral amino-acid substitutions at loops of Phormidium plastocyanin far from the copper site. Notably, mutation P49G/G50P confers a redox-dependent thermal stability similar to that of the mesophilic plastocyanin. Moreover, X-ray absorption spectroscopy reveals that P49G/G50P mutation makes the electron density distribution at the oxidised copper site shift towards that of Synechocystis plastocyanin.
Collapse
Affiliation(s)
- Francisco J Muñoz-López
- Instituto de Bioquímica Vegetal y Fotosíntesis, Universidad de Sevilla y CSIC, Sevilla, Spain
| | | | | | | | | | | | | |
Collapse
|
14
|
Schlarb-Ridley BG, Navarro JA, Spencer M, Bendall DS, Hervás M, Howe CJ, De La Rosa MA. Role of electrostatics in the interaction between plastocyanin and photosystem I of the cyanobacterium Phormidium laminosum. EUROPEAN JOURNAL OF BIOCHEMISTRY 2002; 269:5893-902. [PMID: 12444978 DOI: 10.1046/j.1432-1033.2002.03314.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The interactions between photosystem I and five charge mutants of plastocyanin from the cyanobacterium Phormidium laminosum were investigated in vitro. The dependence of the overall rate constant of reaction, k2, on ionic strength was investigated using laser flash photolysis. The rate constant of the wild-type reaction increased with ionic strength, indicating repulsion between the reaction partners. Removing a negative charge on plastocyanin (D44A) accelerated the reaction and made it independent of ionic strength; removing a positive charge adjacent to D44 (K53A) had little effect. Neutralizing and inverting the charge on R93 slowed the reaction down and increased the repulsion. Specific effects of MgCl2 were observed for mutants K53A, R93Q and R93E. Thermodynamic analysis of the transition state revealed positive activation entropies, suggesting partial desolvation of the interface in the transition state. In comparison with plants, plastocyanin and photosystem I of Phormidium laminosum react slowly at low ionic strength, whereas the two systems have similar rates in the range of physiological salt concentrations. We conclude that in P. laminosum, in contrast with plants in vitro, hydrophobic interactions are more important than electrostatics for the reactions of plastocyanin, both with photosystem I (this paper) and with cytochrome f[Schlarb-Ridley, B.G., Bendall, D.S. & Howe, C.J. (2002) Biochemistry41, 3279-3285]. We discuss the implications of this conclusion for the divergent evolution of cyanobacterial and plant plastocyanins.
Collapse
Affiliation(s)
- Beatrix G Schlarb-Ridley
- Department of Biochemistry and Cambridge Centre for Molecular Recognition, University of Cambridge, UK.
| | | | | | | | | | | | | |
Collapse
|
15
|
Ruffle SV, Mustafa AO, Kitmitto A, Holzenburg A, Ford RC. The location of plastocyanin in vascular plant photosystem I. J Biol Chem 2002; 277:25692-6. [PMID: 11976339 DOI: 10.1074/jbc.m202670200] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
We have studied the binding sites of the electron donor and acceptor proteins of vascular plant photosystem I by electron microscopy/crystallography. Previously, we identified the binding site for the electron acceptor (ferredoxin). In this paper we complete these studies with the characterization of the electron donor (plastocyanin) binding site. After cross-linking, plastocyanin is detected using Fourier difference analysis of two dimensionally ordered arrays of photosystem I located at the periphery of chloroplast grana. Plastocyanin binds in a small cavity on the lumenal surface of photosystem I, close to the center and with a slight bias toward the PsaL subunit of the complex. The recent release of the full coordinates for the cyanobacterial photosystem I reaction center has allowed a detailed comparison between the structures of the eukaryotic and prokaryotic systems. This reveals a very close homology, which is particularly striking for the lumenal side of photosystem I.
Collapse
Affiliation(s)
- Stuart V Ruffle
- School of Biological Sciences, University of Exeter, United Kingdom
| | | | | | | | | |
Collapse
|
16
|
Molina-Heredia FP, Balme A, Hervás M, Navarro JA, De la Rosa MA. A comparative structural and functional analysis of cytochrome cM cytochrome c6 and plastocyanin from the cyanobacterium Synechocystis sp. PCC 6803. FEBS Lett 2002; 517:50-4. [PMID: 12062408 DOI: 10.1016/s0014-5793(02)02576-0] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Cytochrome cM is a new c-class photosynthetic haem protein whose physiological role is still unknown. It has been proposed previously that cytochrome cM can replace cytochrome c6 and plastocyanin in transferring electrons between the two membrane complexes cytochrome b6-f and photosystem I in organisms growing under stress conditions. The experimental evidence herein provided allows us to discard such a hypothesis. We report a procedure to overexpress cytochrome cM from the cyanobacterium Synechocystis sp. PCC 6803 in Escherichia coli cells in mg quantities. This has allowed us to perform a comparative laser flash-induced kinetic analysis of photosystem I reduction by the three metalloproteins from Synechocystis. The bimolecular rate constant for the overall reaction is up to 100 times lower with cytochrome cM than with cytochrome c6 or plastocyanin. In addition, the redox potential value and surface electrostatic potential distribution of cytochrome cM are quite different from those of cytochrome c6 and plastocyanin. These findings strongly indicate that cytochrome cM cannot be recognised by and interact with the same redox partners as the other two metalloproteins.
Collapse
Affiliation(s)
- Fernando P Molina-Heredia
- Instituto de Bioquímica Vegetal y Fotosíntesis, Centro Isla de la Cartuja, Universidad de Sevilla y CSIC, Américo Vespucio s/n, Sevilla, Spain
| | | | | | | | | |
Collapse
|
17
|
De la Rosa MA, Navarro JA, Díaz-Quintana A, De la Cerda B, Molina-Heredia FP, Balme A, Murdoch PDS, Díaz-Moreno I, Durán RV, Hervás M. An evolutionary analysis of the reaction mechanisms of photosystem I reduction by cytochrome c(6) and plastocyanin. Bioelectrochemistry 2002; 55:41-5. [PMID: 11786337 DOI: 10.1016/s1567-5394(01)00136-0] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Photosystem I reduction by the soluble metalloproteins cytochrome c(6) and plastocyanin, which are alternatively synthesized by some photosynthetic organisms depending on the relative availability of copper and iron, has been investigated in cyanobacteria, green algae and plants. The reaction mechanism is classified in three different types on the basis of the affinity of the membrane complex towards its electron donor protein. The role of electrostatic interactions in forming an intermediate transient complex, as well as the structural and functional similarities of cytochrome c(6) and plastocyanin are analysed from an evolutionary point of view. The proposal made is that the heme protein was first "discovered" by nature, when iron was much more abundant on the Earth's surface, and replaced by plastocyanin when copper became available because of the oxidizing conditions of the new atmosphere.
Collapse
Affiliation(s)
- Miguel A De la Rosa
- Instituto de Bioquímica Vegetal y Fotosíntesis, Universidad de Sevilla y Consejo Superior de Investigaciones Científicas, Américo Vespucio s/n, E-41092 Seville, Spain.
| | | | | | | | | | | | | | | | | | | |
Collapse
|
18
|
Baymann F, Brugna M, Mühlenhoff U, Nitschke W. Daddy, where did (PS)I come from? BIOCHIMICA ET BIOPHYSICA ACTA 2001; 1507:291-310. [PMID: 11687221 DOI: 10.1016/s0005-2728(01)00209-2] [Citation(s) in RCA: 83] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
The reacton centre I (RCI)-type photosystems from plants, cyano-, helio- and green sulphur bacteria are compared and the essential properties of an archetypal RCI are deduced. Species containing RCI-type photosystems most probably cluster together on a common branch of the phylogenetic tree. The predicted branching order is green sulphur, helio- and cyanobacteria. Striking similarities between RCI- and RCII-type photosystems recently became apparent in the three-dimensional structures of photosystem I (PSI), PSII and RCII. The phylogenetic relationship between all presently known photosystems is analysed suggesting (a) RCI as the ancestral photosystem and (b) the descendence of PSII from RCI via gene duplication and gene splitting. An evolutionary model trying to rationalise available data is presented.
Collapse
Affiliation(s)
- F Baymann
- Laboratoire de Bioénergétique et Ingénierie des Protéines, Institut de Biologie Structurale et Microbiologie, Marseille, France
| | | | | | | |
Collapse
|
19
|
Molina-Heredia FP, Hervás M, Navarro JA, De la Rosa MA. A single arginyl residue in plastocyanin and in cytochrome c(6) from the cyanobacterium Anabaena sp. PCC 7119 is required for efficient reduction of photosystem I. J Biol Chem 2001; 276:601-5. [PMID: 11013249 DOI: 10.1074/jbc.m007081200] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Positively charged plastocyanin from Anabaena sp. PCC 7119 was investigated by site-directed mutagenesis. The reactivity of its mutants toward photosystem I was analyzed by laser flash spectroscopy. Replacement of arginine at position 88, which is adjacent to the copper ligand His-87, by glutamine and, in particular, by glutamate makes plastocyanin reduce its availability for transferring electrons to photosystem I. Such a residue in the copper protein thus appears to be isofunctional with Arg-64 (which is close to the heme group) in cytochrome c(6) from Anabaena (Molina-Heredia, F. P., Diaz-Quintana, A., Hervás, M., Navarro, J. A., and De la Rosa, M. A. (1999) J. Biol. Chem. 274, 33565-33570) and Synechocystis (De la Cerda, B., Diaz-Quintana, A., Navarro, J. A. , Hervás, M., and De la Rosa, M. A. (1999) J. Biol. Chem. 274, 13292-13297). Other mutations concern specific residues of plastocyanin either at its positively charged east face (D49K, H57A, H57E, K58A, K58E, Y83A, and Y83F) or at its north hydrophobic pole (L12A, K33A, and K33E). Mutations altering the surface electrostatic potential distribution allow the copper protein to modulate its kinetic efficiency: the more positively charged the interaction site, the higher the rate constant. Whereas replacement of Tyr-83 by either alanine or phenylalanine has no effect on the kinetics of photosystem I reduction, Leu-12 and Lys-33 are essential for the reactivity of plastocyanin.
Collapse
Affiliation(s)
- F P Molina-Heredia
- Instituto de Bioquimica Vegetal y Fotosintesis, Centro de Investigaciones Cientificas Isla de la Cartuja, Universidad de Sevilla y Consejo Superior de Investigaciones Cientificas, Américo Vespucio s/n, 41092 Sevilla, Spain
| | | | | | | |
Collapse
|
20
|
Hope AB. Electron transfers amongst cytochrome f, plastocyanin and photosystem I: kinetics and mechanisms. BIOCHIMICA ET BIOPHYSICA ACTA 2000; 1456:5-26. [PMID: 10611452 DOI: 10.1016/s0005-2728(99)00101-2] [Citation(s) in RCA: 166] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The review covers the theory and practice of the determination of kinetic constants for the electron transfer reactions in chloroplast thylakoid membranes between plastocyanin and cytochrome f in cytochrome bf complexes, and between plastocyanin and the reaction centre of photosystem I. Effects of ionic strength and pH are featured. The contribution of mutant studies is included. It is concluded that nearly all data from in vitro experiments can be interpreted with a reaction scheme in which an encounter complex between donor and acceptor is formed by long-range electrostatic attraction, followed by rearrangement during which metal centres become close enough for rapid intra-complex electron transfer. In vivo experiments so far cast doubt on this particular sequence, but their interpretation is not straightforward. Means of modelling the bimolecular complex between cytochrome f and plastocyanin are outlined, and two likely structures are illustrated. The complex formed by plastocyanin and photosystem I in higher plants involves the PsaF subunit, but its structure has not been fully determined.
Collapse
Affiliation(s)
- A B Hope
- School of Biological Sciences, Faculty of Science and Engineering, Flinders University, GPO Box 2100, Adelaide, SA, Australia.
| |
Collapse
|
21
|
Molina-Heredia FP, Díaz-Quintana A, Hervás M, Navarro JA, De La Rosa MA. Site-directed mutagenesis of cytochrome c(6) from Anabaena species PCC 7119. Identification of surface residues of the hemeprotein involved in photosystem I reduction. J Biol Chem 1999; 274:33565-70. [PMID: 10559243 DOI: 10.1074/jbc.274.47.33565] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
A number of surface residues of cytochrome c(6) from the cyanobacterium Anabaena sp. PCC 7119 have been modified by site-directed mutagenesis. Changes were made in six amino acids, two near the heme group (Val-25 and Lys-29) and four in the positively charged patch (Lys-62, Arg-64, Lys-66, and Asp-72). The reactivity of mutants toward the membrane-anchored complex photosystem I was analyzed by laser flash absorption spectroscopy. The experimental results indicate that cytochrome c(6) possesses two areas involved in the redox interaction with photosystem I: 1) a positively charged patch that may drive its electrostatic attractive movement toward photosystem I to form a transient complex and 2) a hydrophobic region at the edge of the heme pocket that may provide the contact surface for the transfer of electrons to P(700). The isofunctionality of these two areas with those found in plastocyanin (which acts as an alternative electron carrier playing the same role as cytochrome c(6)) are evident.
Collapse
Affiliation(s)
- F P Molina-Heredia
- Instituto de Bioquímica Vegetal y Fotosíntesis, Universidad de Sevilla y Consejo Superior de Investigaciones Científicas, Centro Isla de la Cartuja, Américo Vespucio s/n, 41092 Sevilla, Spain
| | | | | | | | | |
Collapse
|
22
|
De la Cerda B, Díaz-Quintana A, Navarro JA, Hervás M, De la Rosa MA. Site-directed mutagenesis of cytochrome c6 from Synechocystis sp. PCC 6803. The heme protein possesses a negatively charged area that may be isofunctional with the acidic patch of plastocyanin. J Biol Chem 1999; 274:13292-7. [PMID: 10224089 DOI: 10.1074/jbc.274.19.13292] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
This paper reports the first site-directed mutagenesis analysis of any cytochrome c6, a heme protein that performs the same function as the copper-protein plastocyanin in the electron transport chain of photosynthetic organisms. Photosystem I reduction by the mutants of cytochrome c6 from the cyanobacterium Synechocystis sp. PCC 6803 has been studied by laser flash absorption spectroscopy. Their kinetic efficiency and thermodynamic properties have been compared with those of plastocyanin mutants from the same organism. Such a comparative study reveals that aspartates at positions 70 and 72 in cytochrome c6 are located in an acidic patch that may be isofunctional with the well known "south-east" patch of plastocyanin. Calculations of surface electrostatic potential distribution in the mutants of cytochrome c6 and plastocyanin indicate that the changes in protein reactivity depend on the surface electrostatic potential pattern rather than on the net charge modification induced by mutagenesis. Phe-64, which is close to the heme group and may be the counterpart of Tyr-83 in plastocyanin, does not appear to be involved in the electron transfer to photosystem I. In contrast, Arg-67, which is at the edge of the cytochrome c6 acidic area, seems to be crucial for the interaction with the reaction center.
Collapse
Affiliation(s)
- B De la Cerda
- Instituto de Bioquímica Vegetal y Fotosíntesis, Universidad de Sevilla y CSIC, Centro Isla de la Cartuja, Américo Vespucio s/n, 41092 Sevilla, Spain
| | | | | | | | | |
Collapse
|
23
|
Ivković-Jensen MM, Ullmann GM, Crnogorac MM, Ejdebäck M, Young S, Hansson O, Kostić NM. Comparing the rates and the activation parameters for the forward reaction between the triplet state of zinc cytochrome c and cupriplastocyanin and the back reaction between the zinc cytochrome c cation radical and cuproplastocyanin. Biochemistry 1999; 38:1589-97. [PMID: 9931026 DOI: 10.1021/bi9817156] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
This is a comparative study of the photoinduced (so-called forward) electron-transfer reaction 3Zncyt/pc(II) --> Zncyt+/pc(I), between the triplet state of zinc cytochrome c (3Zncyt) and cupriplastocyanin [pc(II)], and the thermal (so-called back) electron-transfer reaction Zncyt+/pc(I) --> Zncyt/pc(II), between the cation (radical) of zinc cytochrome c (Zncyt+) and cuproplastocyanin [pc(I)], which follows it. Both reactions occur between associated (docked) reactants, and the respective unimolecular rate constants are kF and kB. Our previous studies showed that the forward reaction is gated by a rearrangement of the diprotein complex. Now we examine the back reaction and complare the two. We study the effects of temperature (in the range 273.3-302.9 K) and viscosity (in the range 1.00-17.4 cP) on the rate constants and determine enthalpies (DeltaH), entropies (DeltaS), and free energies (DeltaG) of activation. We compare wild-type spinach plastocyanin, the single mutants Tyr83Leu and Glu59Lys, and the double mutant Glu59Lys/Glu60Gln. The rate constant kB for wild-type spinach plastocyanin and its mutants markedly depends on viscosity, an indication that the back reaction is also gated. The activation parameters DeltaH and DeltaS show that the forward and back reactions have similar mechanisms, involving a rearrangement of the diprotein complex from the initial binding configuration to the reactive configuration. The rearrangements of the complexes 3Zncyt/pc(II) and Zncyt+/pc(I) that gate their respective reactions are similar but not identical. Since the back reaction of all plastocyanin variants is faster than the forward reaction, the difference in free energy between the docking and the reactive configuration is smaller for the back reaction than for the forward reaction. This difference is explained by the change in the electrostatic potential on the plastocyanin surface as Cu(II) is reduced to Cu(I). It is the smaller DeltaH that makes DeltaG smaller for the back reaction than for the forward reaction.
Collapse
|
24
|
Ivković-Jensen MM, Ullmann GM, Young S, Hansson O, Crnogorac MM, Ejdebäck M, Kostić NM. Effects of single and double mutations in plastocyanin on the rate constant and activation parameters for the rearrangement gating the electron-transfer reaction between the triplet state of zinc cytochrome c and cupriplastocyanin. Biochemistry 1998; 37:9557-69. [PMID: 9649339 DOI: 10.1021/bi9802871] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
The unimolecular rate constant for the photoinduced electron-transfer reaction 3Zncyt/pc(II) --> Zncyt+/pc(I) within the electrostatic complex of zinc cytochrome c and spinach cupriplastocyanin is kF. We report the effects on kF of the following factors, all at pH 7.0: 12 single mutations on the plastocyanin surface (Leu12Asn, Leu12Glu, Leu12Lys, Asp42Asn, Asp42Lys, Glu43Asn, Glu59Gln, Glu59Lys, Glu60Gln, Glu60Lys, Gln88Glu, and Gln88Lys), the double mutation Glu59Lys/Glu60Gln, temperature (in the range 273.3-302.9 K), and solution viscosity (in the range 1. 00-116.0 cP) at 283.2 and 293.2 K. We also report the effects of the plastocyanin mutations on the association constant (Ka) and the corresponding free energy of association (DeltaGa) with zinc cytochrome c at 298.2 K. Dependence of kF on temperature yielded the activation parameters DeltaH, DeltaS, and DeltaG. Dependence of kF on solution viscosity yielded the protein friction and confirmed the DeltaG values determined from the temperature dependence. The aforementioned intracomplex reaction is not a simple electron-transfer reaction because donor-acceptor electronic coupling (HAB) and reorganizational energy (lambda), obtained by fitting of the temperature dependence of kF to the Marcus equation, deviate from the expectations based on precedents and because kF greatly depends on viscosity. This last dependence and the fact that certain mutations affect Ka but not kF are two lines of evidence against the mechanism in which the electron-transfer step is coupled with the faster, but thermodynamically unfavorable, rearrangement step. The electron-transfer reaction is gated by the slower, and thus rate determining, structural rearrangement of the diprotein complex; the rate constant kF corresponds to this rearrangement. Isokinetic correlation of DeltaH and DeltaS parameters and Coulombic energies of the various configurations of the Zncyt/pc(II) complex consistently show that the rearrangement is a facile configurational fluctuation of the associated proteins, qualitatively the same process regardless of the mutations in plastocyanin. Correlation of kF with the orientation of the cupriplastocyanin dipole moment indicates that the reactive configuration of the diprotein complex involves the area near the residue 59, between the upper acidic cluster and the hydrophobic patch. Kinetic effects and noneffects of plastocyanin mutations show that the rearrangement from the initial (docking) configuration, which involves both acidic clusters, to the reactive configuration does not involve the lower acidic cluster and the hydrophobic patch but involves the upper acidic cluster and the area near the residue 88.
Collapse
|
25
|
Molina-Heredia FP, Hervás M, Navarro JA, De la Rosa MA. Cloning and correct expression in Escherichia coli of the petE and petJ genes respectively encoding plastocyanin and cytochrome c6 from the cyanobacterium Anabaena sp. PCC 7119. Biochem Biophys Res Commun 1998; 243:302-6. [PMID: 9473522 DOI: 10.1006/bbrc.1997.7953] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The genes coding for plastocyanin (petE) and cytochrome c6 (petJ) from Anabaena sp. PCC 7119 have been cloned and properly expressed in Escherichia coli. The recombinant proteins are identical to those purified from the cyanobacterial cells. The products of both the petE and petJ genes are correctly processed in E. coli, as deduced from their identical N-terminal amino acid sequences as compared with those of the metalloproteins isolated from the cyanobacterium. Physicochemical and functional properties of the native and recombinant protein preparations are also identical, thereby confirming that expression of petE and petJ genes in E. coli is an adequate tool to address the study of the structure/function relationships in plastocyanin and cytochrome c6 from Anabaena by site-directed mutagenesis.
Collapse
Affiliation(s)
- F P Molina-Heredia
- Instituto de Bioquímica Vegetal y Fotosíntesis, Centro Isla de la Cartuja, Universidad de Sevilla, Spain
| | | | | | | |
Collapse
|