1
|
Murillo-López J, Zinovjev K, Pereira H, Caniuguir A, Garratt R, Babul J, Recabarren R, Alzate-Morales J, Caballero J, Tuñón I, Cabrera R. Studying the phosphoryl transfer mechanism of the E. coli phosphofructokinase-2: from X-ray structure to quantum mechanics/molecular mechanics simulations. Chem Sci 2019; 10:2882-2892. [PMID: 30996866 PMCID: PMC6429617 DOI: 10.1039/c9sc00094a] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2019] [Accepted: 01/24/2019] [Indexed: 12/31/2022] Open
Abstract
Phosphofructokinases catalyze the ATP-dependent phosphorylation of fructose-6-phosphate and they are highly regulated.
Phosphofructokinases (Pfks) catalyze the ATP-dependent phosphorylation of fructose-6-phosphate (F6P) and they are regulated in a wide variety of organisms. Although numerous aspects of the kinetics and regulation have been characterized for Pfks, the knowledge about the mechanism of the phosphoryl transfer reaction and the transition state lags behind. In this work, we describe the X-ray crystal structure of the homodimeric Pfk-2 from E. coli, which contains products in one site and reactants in the other, as well as an additional ATP molecule in the inhibitory allosteric site adjacent to the reactants. This complex was previously predicted when studying the kinetic mechanism of ATP inhibition. After removing the allosteric ATP, molecular dynamic (MD) simulations revealed conformational changes related to domain packing, as well as stable interactions of Lys27 and Asp256 with donor (ATP) and acceptor (fructose-6-) groups, and of Asp166 with Mg2+. The phosphoryl transfer reaction mechanism catalyzed by Pfk-2 was investigated through Quantum Mechanics/Molecular Mechanics (QM/MM) simulations using a combination of the string method and a path-collective variable for the exploration of its free energy surface. The calculated activation free energies showed that a dissociative mechanism, occurring with a metaphosphate intermediate formation followed by a proton transfer to Asp256, is more favorable than an associative one. The structural analysis reveals the role of Asp256 acting as a catalytic base and Lys27 stabilizing the transition state of the dissociative mechanism.
Collapse
Affiliation(s)
- Juliana Murillo-López
- Centro de Bioinformática y Simulación Molecular (CBSM) , Facultad de Ingeniería , Universidad de Talca , 1 Poniente 1141 , Talca , Chile .
| | - Kirill Zinovjev
- Departament de Química Física , Universitat de València , 46100 Burjassot , Spain .
| | - Humberto Pereira
- Instituto de Física de São Carlos , Universidade de São Paulo , São Paulo , Brazil
| | - Andres Caniuguir
- Departamento de Biología , Facultad de Ciencias , Universidad de Chile , Santiago , Chile .
| | - Richard Garratt
- Instituto de Física de São Carlos , Universidade de São Paulo , São Paulo , Brazil
| | - Jorge Babul
- Departamento de Biología , Facultad de Ciencias , Universidad de Chile , Santiago , Chile .
| | - Rodrigo Recabarren
- Centro de Bioinformática y Simulación Molecular (CBSM) , Facultad de Ingeniería , Universidad de Talca , 1 Poniente 1141 , Talca , Chile .
| | - Jans Alzate-Morales
- Centro de Bioinformática y Simulación Molecular (CBSM) , Facultad de Ingeniería , Universidad de Talca , 1 Poniente 1141 , Talca , Chile .
| | - Julio Caballero
- Centro de Bioinformática y Simulación Molecular (CBSM) , Facultad de Ingeniería , Universidad de Talca , 1 Poniente 1141 , Talca , Chile .
| | - Iñaki Tuñón
- Departament de Química Física , Universitat de València , 46100 Burjassot , Spain .
| | - Ricardo Cabrera
- Departamento de Biología , Facultad de Ciencias , Universidad de Chile , Santiago , Chile .
| |
Collapse
|
2
|
Dang T, Ingram-Smith C. Investigation of pyrophosphate versus ATP substrate selection in the Entamoeba histolytica acetate kinase. Sci Rep 2017; 7:5912. [PMID: 28724909 PMCID: PMC5517563 DOI: 10.1038/s41598-017-06156-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2017] [Accepted: 06/08/2017] [Indexed: 12/21/2022] Open
Abstract
Acetate kinase (ACK; E.C. 2.7.2.1), which catalyzes the interconversion of acetate and acetyl phosphate, is nearly ubiquitous in bacteria but is present only in one genus of archaea and certain eukaryotic microbes. All ACKs utilize ATP/ADP as the phosphoryl donor/acceptor in the respective directions of the reaction (acetate + ATP \documentclass[12pt]{minimal}
\usepackage{amsmath}
\usepackage{wasysym}
\usepackage{amsfonts}
\usepackage{amssymb}
\usepackage{amsbsy}
\usepackage{mathrsfs}
\usepackage{upgreek}
\setlength{\oddsidemargin}{-69pt}
\begin{document}$${\boldsymbol{\leftrightarrows }}$$\end{document}⇆ acetyl phosphate + ADP), with the exception of the Entamoeba histolytica ACK (EhACK) which uses pyrophosphate (PPi)/inorganic phosphate (Pi) (acetyl phosphate + Pi
\documentclass[12pt]{minimal}
\usepackage{amsmath}
\usepackage{wasysym}
\usepackage{amsfonts}
\usepackage{amssymb}
\usepackage{amsbsy}
\usepackage{mathrsfs}
\usepackage{upgreek}
\setlength{\oddsidemargin}{-69pt}
\begin{document}$${\boldsymbol{\leftrightarrows }}$$\end{document}⇆ acetate + PPi). Structural analysis and modeling of EhACK indicated steric hindrance by active site residues constricts entry to the adenosine pocket as compared to ATP-utilizing Methanosarcina thermophila ACK (MtACK). Reciprocal alterations were made to enlarge the adenosine pocket of EhACK and reduce that of MtACK. The EhACK variants showed a step-wise increase in ADP and ATP binding but were still unable to use these as substrates, and enzymatic activity with Pi/PPi was negatively impacted. Consistent with this, ATP utilization by MtACK variants was negatively affected but the alterations were not sufficient to convert this enzyme to Pi/PPi utilization. Our results suggest that controlling access to the adenosine pocket can contribute to substrate specificity but is not the sole determinant.
Collapse
Affiliation(s)
- Thanh Dang
- Department of Genetics and Biochemistry and the Eukaryotic Pathogens Innovation Center, Clemson University, Clemson, SC, 29634, USA
| | - Cheryl Ingram-Smith
- Department of Genetics and Biochemistry and the Eukaryotic Pathogens Innovation Center, Clemson University, Clemson, SC, 29634, USA.
| |
Collapse
|
3
|
Ferry JG. Acetate Metabolism in Anaerobes from the Domain Archaea. Life (Basel) 2015; 5:1454-71. [PMID: 26068860 PMCID: PMC4500148 DOI: 10.3390/life5021454] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2015] [Accepted: 06/01/2015] [Indexed: 01/26/2023] Open
Abstract
Acetate and acetyl-CoA play fundamental roles in all of biology, including anaerobic prokaryotes from the domains Bacteria and Archaea, which compose an estimated quarter of all living protoplasm in Earth's biosphere. Anaerobes from the domain Archaea contribute to the global carbon cycle by metabolizing acetate as a growth substrate or product. They are components of anaerobic microbial food chains converting complex organic matter to methane, and many fix CO2 into cell material via synthesis of acetyl-CoA. They are found in a diversity of ecological habitats ranging from the digestive tracts of insects to deep-sea hydrothermal vents, and synthesize a plethora of novel enzymes with biotechnological potential. Ecological investigations suggest that still more acetate-metabolizing species with novel properties await discovery.
Collapse
Affiliation(s)
- James G Ferry
- Department of Biochemistry and Molecular Biology, Pennsylvania State University, University Park, PA 16802, USA.
| |
Collapse
|