Issue 44, 2020

Single molecule force spectroscopy reveals that a two-coordinate ferric site is critical for the folding of holo-rubredoxin

Abstract

Metalloproteins play important roles in a wide range of biological processes. The folding process of metalloproteins is complex due to the synergistic effects of the folding of their polypeptide chains and the incorporation of metal cofactors. The folding mechanism of the simplest iron–sulfur protein rubredoxin, which contains one ferric ion coordinated by four cysteinyl sulfurs, is revealed using optical tweezers for the first time. The folding of the rubredoxin polypeptide chain is rapid and robust, while the reconstitution of the iron–sulfur center is greatly dependent upon the coordination state of the ferric ion on the unfolded polypeptide chain. If the ferric ion is coordinated by two neighboring cysteines, rubredoxin can readily fold with the iron–sulfur center fully reconstituted. However, if the ferric ion is only mono-coordinated, rubredoxin can fold but the iron–sulfur center is not reconstituted. Our results suggested that the folding of holo-rubredoxin follows a novel binding−folding−reconstitution mechanism, which is distinct from the folding mechanisms proposed for the folding of metalloproteins. Our study highlights the critical importance of the two-coordinate ferric site in the folding of holo-rubredoxin, which may have some important implications to our understanding of the folding mechanism of more complex metalloproteins in vivo.

Graphical abstract: Single molecule force spectroscopy reveals that a two-coordinate ferric site is critical for the folding of holo-rubredoxin

Supplementary files

Article information

Article type
Paper
Submitted
31 aug 2020
Accepted
14 okt 2020
First published
14 okt 2020

Nanoscale, 2020,12, 22564-22573

Single molecule force spectroscopy reveals that a two-coordinate ferric site is critical for the folding of holo-rubredoxin

J. Li and H. Li, Nanoscale, 2020, 12, 22564 DOI: 10.1039/D0NR06275H

To request permission to reproduce material from this article, please go to the Copyright Clearance Center request page.

If you are an author contributing to an RSC publication, you do not need to request permission provided correct acknowledgement is given.

If you are the author of this article, you do not need to request permission to reproduce figures and diagrams provided correct acknowledgement is given. If you want to reproduce the whole article in a third-party publication (excluding your thesis/dissertation for which permission is not required) please go to the Copyright Clearance Center request page.

Read more about how to correctly acknowledge RSC content.

Social activity

Spotlight

Advertisements