Skip to main content

Research Repository

Advanced Search

The suppressor of copper sensitivity protein C from Caulobacter crescentus is a trimeric disulfide isomerase that binds copper(I) with subpicomolar affinity

Petit, Guillaume A.; Hong, Yaoqin; Djoko, Karrera Y.; Whitten, Andrew E.; Furlong, Emily J.; McCoy, Airlie J.; Gulbis, Jacqueline M.; Totsika, Makrina; Martin, Jennifer L.; Halili, Maria A.

The suppressor of copper sensitivity protein C from Caulobacter crescentus is a trimeric disulfide isomerase that binds copper(I) with subpicomolar affinity Thumbnail


Authors

Guillaume A. Petit

Yaoqin Hong

Andrew E. Whitten

Emily J. Furlong

Airlie J. McCoy

Jacqueline M. Gulbis

Makrina Totsika

Jennifer L. Martin

Maria A. Halili



Abstract

The introduction of disulfide bonds into periplasmic proteins is a critical process in many Gram-negative bacteria. The formation and regulation of protein disulfide bonds have been linked to the production of virulence factors. Understanding the different pathways involved in this process is important in the development of strategies to disarm pathogenic bacteria. The well characterized disulfide bond-forming (DSB) proteins play a key role by introducing or isomerizing disulfide bonds between cysteines in substrate proteins. Curiously, the suppressor of copper sensitivity C proteins (ScsCs), which are part of the bacterial copper-resistance response, share structural and functional similarities with DSB oxidase and isomerase proteins, including the presence of a catalytic thioredoxin domain. However, the oxidoreductase activity of ScsC varies with its oligomerization state, which depends on a poorly conserved N-terminal domain. Here, the structure and function of Caulobacter crescentus ScsC (CcScsC) have been characterized. It is shown that CcScsC binds copper in the copper(I) form with subpicomolar affinity and that its isomerase activity is comparable to that of Escherichia coli DsbC, the prototypical dimeric bacterial isomerase. It is also reported that CcScsC functionally complements trimeric Proteus mirabilis ScsC (PmScsC) in vivo, enabling the swarming of P. mirabilis in the presence of copper. Using mass photometry and small-angle X-ray scattering (SAXS) the protein is demonstrated to be trimeric in solution, like PmScsC, and not dimeric like EcDsbC. The crystal structure of CcScsC was also determined at a resolution of 2.6 Å, confirming the trimeric state and indicating that the trimerization results from interactions between the N-terminal α-helical domains of three CcScsC protomers. The SAXS data analysis suggested that the protomers are dynamic, like those of PmScsC, and are able to sample different conformations in solution.

Citation

Petit, G. A., Hong, Y., Djoko, K. Y., Whitten, A. E., Furlong, E. J., McCoy, A. J., …Halili, M. A. (2022). The suppressor of copper sensitivity protein C from Caulobacter crescentus is a trimeric disulfide isomerase that binds copper(I) with subpicomolar affinity. Acta Crystallographica Section D: Structural Biology, 78(3), https://doi.org/10.1107/s2059798322000729

Journal Article Type Article
Acceptance Date Jan 21, 2022
Online Publication Date Feb 21, 2022
Publication Date 2022
Deposit Date May 24, 2022
Publicly Available Date May 25, 2022
Journal Acta Crystallographica Section D Structural Biology
Print ISSN 2059-7983
Publisher International Union of Crystallography
Peer Reviewed Peer Reviewed
Volume 78
Issue 3
DOI https://doi.org/10.1107/s2059798322000729

Files

Published Journal Article (3.3 Mb)
PDF

Publisher Licence URL
http://creativecommons.org/licenses/by/4.0/

Copyright Statement
This is an open-access article distributed under the terms of the Creative Commons Attribution (CC-BY) Licence, which permits unrestricted use, distribution, and reproduction in any medium, provided the original authors and source are cited.







You might also like



Downloadable Citations