Please use this identifier to cite or link to this item:
https://hdl.handle.net/10216/110347
Author(s): | Santos, JA Alonso-García, N Macedo-Ribeiro, S Pereira, PJ |
Title: | The unique regulation of iron-sulfur cluster biogenesis in a Gram-positive bacterium |
Publisher: | National Academy of Sciences |
Issue Date: | 2014 |
Abstract: | Iron-sulfur clusters function as cofactors of a wide range of proteins, with diverse molecular roles in both prokaryotic and eukaryotic cells. Dedicated machineries assemble the clusters and deliver them to the final acceptor molecules in a tightly regulated process. In the prototypical Gram-negative bacterium Escherichia coli, the two existing iron-sulfur cluster assembly systems, iron-sulfur cluster (ISC) and sulfur assimilation (SUF) pathways, are closely interconnected. The ISC pathway regulator, IscR, is a transcription factor of the helix-turn-helix type that can coordinate a [2Fe-2S] cluster. Redox conditions and iron or sulfur availability modulate the ligation status of the labile IscR cluster, which in turn determines a switch in DNA sequence specificity of the regulator: cluster-containing IscR can bind to a family of gene promoters (type-1) whereas the clusterless form recognizes only a second group of sequences (type-2). However, iron-sulfur cluster biogenesis in Gram-positive bacteria is not so well characterized, and most organisms of this group display only one of the iron-sulfur cluster assembly systems. A notable exception is the unique Gram-positive dissimilatory metal reducing bacterium Thermincola potens, where genes from both systems could be identified, albeit with a diverging organization from that of Gram-negative bacteria. We demonstrated that one of these genes encodes a functional IscR homolog and is likely involved in the regulation of iron-sulfur cluster biogenesis in T. potens. Structural and biochemical characterization of T. potens and E. coli IscR revealed a strikingly similar architecture and unveiled an unforeseen conservation of the unique mechanism of sequence discrimination characteristic of this distinctive group of transcription regulators. |
Subject: | Crystallography, X-Ray DNA Bacterial/metabolism DNA-Binding Proteins/genetics DNA-Binding Proteins/metabolism Dimerization Escherichia coli K12/genetics Escherichia coli K12/metabolism Escherichia coli Proteins/genetics Escherichia coli Proteins/metabolism Gene Expression Regulation, Bacterial Gram-Positive Bacteria/genetics Gram-Positive Bacteria/metabolism Helix-Turn-Helix Motifs Iron-Sulfur Proteins/genetics Iron-Sulfur Proteins/metabolism Point Mutation Promoter Regions Genetic Protein Structure Tertiary Transcription Factors/genetics Transcription Factors/metabolism |
URI: | http://hdl.handle.net/10216/110347 |
Source: | Proceedings of the National Academy of Sciences of the United States of America, vol. 111(22), p. E2251-60 |
Related Information: | info:eu-repo/grantAgreement/FCT/COMPETE/127722/PT info:eu-repo/grantAgreement/FCT/SFRH/SFRH%2FBD%2F66461%2F2009/PT |
Document Type: | Artigo em Revista Científica Internacional |
Rights: | openAccess |
Appears in Collections: | I3S - Artigo em Revista Científica Internacional |
Files in This Item:
File | Description | Size | Format | |
---|---|---|---|---|
Santos2014.pdf | 1.91 MB | Adobe PDF | View/Open | |
Santos2014_SupMat.pdf | 565.51 kB | Adobe PDF | View/Open |
Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.