TY - JOUR
T1 - Molecular geometries of the heme axial ligands from the triheme cytochrome PpcF from Geobacter metallireducens reveal a conserved heme core architecture
AU - Ferreira, Marisa R.
AU - Fernandes, Tomás M.
AU - Turner, David L.
AU - Salgueiro, Carlos A.
N1 - Funding Information:
This work was supported by Fundação para a Ciência e Tecnologia (FCT) through the following grants: SFRH/BD/132969/2017 (to MRF), SFRH/BD/145039/2019 (to TMF), PTDC/BIA-BQM/31981/2017 (to CAS) and PTDC/BIA-BQM/4967/2020 (to CAS). This work was also supported by the Applied Molecular Biosciences Unit – UCIBIO , which is financed by national funds from FCT ( UIDB/04378/2020 and UIDP/04378/2020 ), and by the project LA/P/0140/2020 of the Associate Laboratory Institute for Health and Bioeconomy – i4HB. The NMR spectrometers are part of the National NMR Network (PTNMR) and are supported by FCT-MCTES ( ROTEIRO/0031/2013 – PINFRA/22161/2016 ) co-funded by FEDER through COMPETE 2020, POCI, and PORL and FCT through PIDDAC.
Publisher Copyright:
© 2022 Elsevier Inc.
PY - 2022/7/15
Y1 - 2022/7/15
N2 - Electroactive Geobacter bacteria can perform extracellular electron transfer and present a wide metabolic versatility. These bacteria reduce organic, toxic and radioactive compounds, and produce electric current while interacting with electrodes, making them interesting targets for numerous biotechnological applications. Their global electrochemical responses rely on an efficient interface between the inside and the cell's exterior, which is driven by the highly abundant periplasmic triheme PpcA-family cytochromes. The functional features of these cytochromes have been studied in G. sulfurreducens and G. metallireducens, and although they share a high degree of structural homology and sequence identity, their properties are quite distinct. In this work, the heme axial ligand geometries and the magnetic properties of PpcF from G. metallireducens were determined. The data obtained constitute important constraints for the determination of its solution structure in the oxidized state and indicate that the (i) heme core architecture; (ii) axial ligands geometries and (iii) magnetic properties of the cytochrome are conserved compared to the other members of the PpcA-families. Furthermore, the results also indicate that the heme arrangement is crucial to maintain an intrinsic regulation of the protein's redox properties and hence its electron transfer efficiency and functionality.
AB - Electroactive Geobacter bacteria can perform extracellular electron transfer and present a wide metabolic versatility. These bacteria reduce organic, toxic and radioactive compounds, and produce electric current while interacting with electrodes, making them interesting targets for numerous biotechnological applications. Their global electrochemical responses rely on an efficient interface between the inside and the cell's exterior, which is driven by the highly abundant periplasmic triheme PpcA-family cytochromes. The functional features of these cytochromes have been studied in G. sulfurreducens and G. metallireducens, and although they share a high degree of structural homology and sequence identity, their properties are quite distinct. In this work, the heme axial ligand geometries and the magnetic properties of PpcF from G. metallireducens were determined. The data obtained constitute important constraints for the determination of its solution structure in the oxidized state and indicate that the (i) heme core architecture; (ii) axial ligands geometries and (iii) magnetic properties of the cytochrome are conserved compared to the other members of the PpcA-families. Furthermore, the results also indicate that the heme arrangement is crucial to maintain an intrinsic regulation of the protein's redox properties and hence its electron transfer efficiency and functionality.
KW - Geobacter
KW - Multiheme cytochromes
KW - Nuclear magnetic resonance
KW - Paramagnetic redox centers
UR - http://www.scopus.com/inward/record.url?scp=85128547775&partnerID=8YFLogxK
U2 - 10.1016/j.abb.2022.109220
DO - 10.1016/j.abb.2022.109220
M3 - Article
C2 - 35430214
AN - SCOPUS:85128547775
SN - 0003-9861
VL - 723
JO - Archives of Biochemistry and Biophysics
JF - Archives of Biochemistry and Biophysics
M1 - 109220
ER -