Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2015 Jun;1853(6):1457-63.
doi: 10.1016/j.bbamcr.2014.10.015. Epub 2014 Oct 28.

IscS from Archaeoglobus fulgidus has no desulfurase activity but may provide a cysteine ligand for [Fe2S2] cluster assembly

Adrien Pagnier  1 , Yvain Nicolet  1 , Juan C Fontecilla-Camps  2
Affiliations
Free article

IscS from Archaeoglobus fulgidus has no desulfurase activity but may provide a cysteine ligand for [Fe2S2] cluster assembly

Adrien Pagnier et al. Biochim Biophys Acta. 2015 Jun.
Free article

Abstract

Iron sulfur ([Fe-S]) clusters are essential prosthetic groups involved in fundamental cell processes such as gene expression regulation, electron transfer and Lewis acid base chemistry. Central components of their biogenesis are pyridoxal-5'-phosphate (PLP) dependent l-cysteine desulfurases, which provide the necessary S atoms for [Fe-S] cluster assembly. The archaeon Archaeoglobus fulgidus (Af) has two ORFs, which although annotated as l-cysteine desulfurases of the ISC type (IscS), lack the essential Lys residue (K199 in Af) that forms a Schiff base with PLP. We have previously determined the structure of an Af(IscU-D35A-IscS)2 complex heterologously expressed in Escherichia coli and found it to contain a [Fe2S2] cluster. In order to understand the origin of sulfide in that structure we have performed a series of functional tests using wild type and mutated forms of AfIscS. In addition, we have determined the crystal structure of an AfIscS-D199K mutant. From these studies we conclude that: i) AfIscS has no desulfurase activity; ii) in our in vitro [Fe2S2] cluster assembly experiments, sulfide ions are non-enzymatically generated by a mixture of iron, l-cysteine and PLP and iii) the physiological role of AfIscS may be to provide a cysteine ligand to the nascent cluster as observed in the [Fe2S2]-Af(IscU-D35A-IscS)2 complex. This article is part of a Special Issue entitled: Fe/S proteins: Analysis, structure, function, biogenesis and diseases.

Keywords: 5′-pyridoxamine; Archaeoglobus fulgidus; IscS; Pyridoxal 5′-phosphate; Schiff base; l-cysteine desulfurase.

PubMed Disclaimer

Similar articles

See all similar articles

Cited by

See all "Cited by" articles

Publication types

MeSH terms

LinkOut - more resources