@article{6c8878c01624431b90693541ce13abba,
title = "Hemes on a string: insights on the functional mechanisms of PgcA from Geobacter sulfurreducens",
abstract = "Microbial extracellular reduction of insoluble compounds requires soluble electron shuttles that diffuse in the environment, freely diffusing cytochromes, or direct contact with cellular conductive appendages that release or harvest electrons to assure a continuous balance between cellular requirements and environmental conditions. In this work, we produced and characterized the three cytochrome domains of PgcA, an extracellular triheme cytochrome that contributes to Fe(III) and Mn(IV) oxides reduction in Geobacter sulfurreducens. The three monoheme domains are structurally homologous, but their heme groups show variable axial coordination and reduction potential values. Electron transfer experiments monitored by NMR and visible spectroscopy show the variable extent to which the domains promiscuously exchange electrons while reducing different electron acceptors. The results suggest that PgcA is part of a new class of cytochromes - microbial heme-tethered redox strings - that use low-complexity protein stretches to bind metals and promote intra- and intermolecular electron transfer events through its cytochrome domains.",
keywords = "electron transfer, Geobacter, Metalloprotein, multiheme cytochromes, nuclear magnetic resonance (NMR), protein domain, Respiratory chain",
author = "Fernandes, {Tom{\'a}s M.} and Silva, {Marta A.} and Leonor Morgado and Salgueiro, {Carlos A.}",
note = "Funding Information: This work was supported by Funda{\c c}{\~a}o para a Ci{\^e}ncia e Tecnologia (FCT) through the following grants: SFRH/BD/145039/2019 (T. M. F.), EXPL/BIA-BQM/0770/2021 (L. M.) and PTDC/BIABQM/4967/2020 (C. A. S.). This work was also supported by national funds from FCT in the scope of the projects (i) UIDP/04378/2020 and UIDB/04378/2020 (Research Unit on Applied Molecular Biosciences – UCIBIO) and (ii) LA/P/0140/2020 (Associate Laboratory Institute for Health and Bioeconomy – i4HB). The NMR spectrometers are part of the National NMR Network and are supported by FCT ( ROTEIRO/0031/2013 and PINFRA/22161/2016 ) cofounded by FEDER through COMPETE 2020, POCI, PORL and FCT through PIDDAC. Funding Information: Elisabete Ferreira (BioLab, UCIBIO, FCT-NOVA) is acknowledged for the technical assistance with the circular dichroism and differential scanning calorimetry experiments. T. M. F. L. M. and C. A. S. conceptualization; T. M. F. M. A. S. L. M. and C. A. S. investigation; T. M. F. M. A. S. L. M. formal analysis; T. M. F. writing–original draft; T. M. F. M. A. S. L. M. and C. A. S. writing–review & editing; T. M. F. visualization; L. M. and C. A. S. supervision; L. M. and C. A. S. funding acquisition; C. A. S. project administration. This work was supported by Funda{\c c}{\~a}o para a Ci{\^e}ncia e Tecnologia (FCT) through the following grants: SFRH/BD/145039/2019 (T. M. F.), EXPL/BIA-BQM/0770/2021 (L. M.) and PTDC/BIABQM/4967/2020 (C. A. S.). This work was also supported by national funds from FCT in the scope of the projects (i) UIDP/04378/2020 and UIDB/04378/2020 (Research Unit on Applied Molecular Biosciences – UCIBIO) and (ii) LA/P/0140/2020 (Associate Laboratory Institute for Health and Bioeconomy – i4HB). The NMR spectrometers are part of the National NMR Network and are supported by FCT (ROTEIRO/0031/2013 and PINFRA/22161/2016) cofounded by FEDER through COMPETE 2020, POCI, PORL and FCT through PIDDAC. Publisher Copyright: {\textcopyright} 2023 The Authors",
year = "2023",
month = oct,
doi = "10.1016/j.jbc.2023.105167",
language = "English",
volume = "299",
journal = "Journal of Biological Chemistry",
issn = "0021-9258",
publisher = "ASBMB - American Society for Biochemistry and Molecular Biology",
number = "10",
}