The SufE sulfur-acceptor protein contains a conserved core structure that mediates interdomain interactions in a variety of redox protein complexes
- PMID: 15522304
- DOI: 10.1016/j.jmb.2004.08.074
The SufE sulfur-acceptor protein contains a conserved core structure that mediates interdomain interactions in a variety of redox protein complexes
Abstract
The isc and suf operons in Escherichia coli represent alternative genetic systems optimized to mediate the essential metabolic process of iron-sulfur cluster (Fe-S) assembly under basal or oxidative-stress conditions, respectively. Some of the proteins in these two operons share strong sequence homology, e.g. the cysteine desulfurases IscS and SufS, and presumably play the same role in the oxygen-sensitive assembly process. However, other proteins in these operons share no significant homology and occur in a mutually exclusive manner in Fe-S assembly operons in other organisms (e.g. IscU and SufE). These latter proteins presumably play distinct roles adapted to the different assembly mechanisms used by the two systems. IscU has three invariant cysteine residues that function as a template for Fe-S assembly while accepting a sulfur atom from IscS. SufE, in contrast, does not function as an Fe-S assembly template but has been suggested to function as a shuttle protein that uses a persulfide linkage to a single invariant cysteine residue to transfer a sulfur atom from SufS to an alternative Fe-S assembly template. Here, we present and analyze the 2.0A crystal structure of E.coli SufE. The structure shows that the persulfide-forming cysteine occurs at the tip of a loop with elevated B-factors, where its side-chain is buried from solvent exposure in a hydrophobic cavity located beneath a highly conserved surface. Despite the lack of sequence homology, the core of SufE shows strong structural similarity to IscU, and the sulfur-acceptor site in SufE coincides with the location of the cysteine residues mediating Fe-S cluster assembly in IscU. Thus, a conserved core structure is implicated in mediating the interactions of both SufE and IscU with the mutually homologous cysteine desulfurase enzymes present in their respective operons. A similar core structure is observed in a domain found in a variety of Fe-S cluster containing flavoenzymes including xanthine dehydrogenase, where it also mediates interdomain interactions. Therefore, the core fold of SufE/IscU has been adapted to mediate interdomain interactions in diverse redox protein systems in the course of evolution.
Similar articles
-
Solution NMR structure of the iron-sulfur cluster assembly protein U (IscU) with zinc bound at the active site.J Mol Biol. 2004 Nov 19;344(2):567-83. doi: 10.1016/j.jmb.2004.08.038. J Mol Biol. 2004. PMID: 15522305
-
How Escherichia coli and Saccharomyces cerevisiae build Fe/S proteins.Adv Microb Physiol. 2005;50:41-101. doi: 10.1016/S0065-2911(05)50002-X. Adv Microb Physiol. 2005. PMID: 16221578
-
The SUF iron-sulfur cluster biosynthetic machinery: sulfur transfer from the SUFS-SUFE complex to SUFA.FEBS Lett. 2007 Apr 3;581(7):1362-8. doi: 10.1016/j.febslet.2007.02.058. Epub 2007 Mar 5. FEBS Lett. 2007. PMID: 17350000
-
Iron-sulfur cluster biosynthesis in bacteria: Mechanisms of cluster assembly and transfer.Arch Biochem Biophys. 2008 Jun 15;474(2):226-37. doi: 10.1016/j.abb.2007.12.014. Epub 2007 Dec 28. Arch Biochem Biophys. 2008. PMID: 18191630 Review.
-
Trafficking in persulfides: delivering sulfur in biosynthetic pathways.Nat Chem Biol. 2006 Apr;2(4):185-94. doi: 10.1038/nchembio779. Nat Chem Biol. 2006. PMID: 16547481 Review.
Cited by
-
Research progress on the biosynthesis and delivery of iron-sulfur clusters in the plastid.Plant Cell Rep. 2023 Aug;42(8):1255-1264. doi: 10.1007/s00299-023-03024-7. Epub 2023 May 9. Plant Cell Rep. 2023. PMID: 37160773 Review.
-
Structural diversity of cysteine desulfurases involved in iron-sulfur cluster biosynthesis.Biophys Physicobiol. 2022 Feb 8;19:1-18. doi: 10.2142/biophysico.bppb-v19.0001. eCollection 2022. Biophys Physicobiol. 2022. PMID: 35377584 Free PMC article.
-
Fe-S cluster biogenesis by the bacterial Suf pathway.Biochim Biophys Acta Mol Cell Res. 2020 Nov;1867(11):118829. doi: 10.1016/j.bbamcr.2020.118829. Epub 2020 Aug 18. Biochim Biophys Acta Mol Cell Res. 2020. PMID: 32822728 Free PMC article. Review.
-
Iron-sulfur clusters biogenesis by the SUF machinery: close to the molecular mechanism understanding.J Biol Inorg Chem. 2018 Jun;23(4):581-596. doi: 10.1007/s00775-017-1527-3. Epub 2017 Dec 26. J Biol Inorg Chem. 2018. PMID: 29280002 Free PMC article. Review.
-
Insights into the inhibited form of the redox-sensitive SufE-like sulfur acceptor CsdE.PLoS One. 2017 Oct 18;12(10):e0186286. doi: 10.1371/journal.pone.0186286. eCollection 2017. PLoS One. 2017. PMID: 29045454 Free PMC article.
Publication types
MeSH terms
Substances
Associated data
- Actions
Grants and funding
LinkOut - more resources
Full Text Sources
Other Literature Sources
Molecular Biology Databases
Miscellaneous