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Title: The Crystal Structure of the Extracellular 11-heme Cytochrome UndA Reveals a Conserved 10-heme Motif and Defined Binding Site for Soluble Iron Chelates.

Abstract

Members of the genus Shewanella translocate deca- or undeca-heme cytochromes to the external cell surface thus enabling respiration using extracellular minerals and polynuclear Fe(III) chelates. The high resolution structure of the first undeca-heme outer membrane cytochrome, UndA, reveals a crossed heme chain with four potential electron ingress/egress sites arranged within four domains. Sequence and structural alignment of UndA and the deca-heme MtrF reveals the extra heme of UndA is inserted between MtrF hemes 6 and 7. The remaining UndA hemes can be superposed over the heme chain of the decaheme MtrF, suggesting that a ten heme core is conserved between outer membrane cytochromes. The UndA structure is the first outer membrane cytochrome to be crystallographically resolved in complex with substrates, an Fe(III)-nitrilotriacetate dimer or an Fe(III)-citrate trimer. The structural resolution of these UndA-Fe(III)-chelate complexes provides a rationale for previous kinetic measurements on UndA and other outer membrane cytochromes.

Authors:
; ; ; ; ; ; ;
Publication Date:
Research Org.:
Pacific Northwest National Lab. (PNNL), Richland, WA (United States)
Sponsoring Org.:
USDOE
OSTI Identifier:
1049014
Report Number(s):
PNNL-SA-89780
KP1702030; TRN: US201217%%285
DOE Contract Number:
AC05-76RL01830
Resource Type:
Journal Article
Resource Relation:
Journal Name: Structure; Journal Volume: 20; Journal Issue: 7
Country of Publication:
United States
Language:
English
Subject:
59 BASIC BIOLOGICAL SCIENCES; 60 APPLIED LIFE SCIENCES; ALIGNMENT; CHAINS; CHELATES; CRYSTAL STRUCTURE; CYTOCHROMES; DIMERS; ELECTRONS; HEME; IRON; KINETICS; MEMBRANES; RESOLUTION; RESPIRATION; SUBSTRATES; crystal structure, extracellular 11-heme cytochrome; soluble iron chelates

Citation Formats

Edwards, Marcus, Hall, Andrea, Shi, Liang, Fredrickson, Jim K., Zachara, John M., Butt, Julea N., Richardson, David, and Clarke, Thomas A. The Crystal Structure of the Extracellular 11-heme Cytochrome UndA Reveals a Conserved 10-heme Motif and Defined Binding Site for Soluble Iron Chelates.. United States: N. p., 2012. Web. doi:10.1016/j.str.2012.04.016.
Edwards, Marcus, Hall, Andrea, Shi, Liang, Fredrickson, Jim K., Zachara, John M., Butt, Julea N., Richardson, David, & Clarke, Thomas A. The Crystal Structure of the Extracellular 11-heme Cytochrome UndA Reveals a Conserved 10-heme Motif and Defined Binding Site for Soluble Iron Chelates.. United States. doi:10.1016/j.str.2012.04.016.
Edwards, Marcus, Hall, Andrea, Shi, Liang, Fredrickson, Jim K., Zachara, John M., Butt, Julea N., Richardson, David, and Clarke, Thomas A. Tue . "The Crystal Structure of the Extracellular 11-heme Cytochrome UndA Reveals a Conserved 10-heme Motif and Defined Binding Site for Soluble Iron Chelates.". United States. doi:10.1016/j.str.2012.04.016.
@article{osti_1049014,
title = {The Crystal Structure of the Extracellular 11-heme Cytochrome UndA Reveals a Conserved 10-heme Motif and Defined Binding Site for Soluble Iron Chelates.},
author = {Edwards, Marcus and Hall, Andrea and Shi, Liang and Fredrickson, Jim K. and Zachara, John M. and Butt, Julea N. and Richardson, David and Clarke, Thomas A.},
abstractNote = {Members of the genus Shewanella translocate deca- or undeca-heme cytochromes to the external cell surface thus enabling respiration using extracellular minerals and polynuclear Fe(III) chelates. The high resolution structure of the first undeca-heme outer membrane cytochrome, UndA, reveals a crossed heme chain with four potential electron ingress/egress sites arranged within four domains. Sequence and structural alignment of UndA and the deca-heme MtrF reveals the extra heme of UndA is inserted between MtrF hemes 6 and 7. The remaining UndA hemes can be superposed over the heme chain of the decaheme MtrF, suggesting that a ten heme core is conserved between outer membrane cytochromes. The UndA structure is the first outer membrane cytochrome to be crystallographically resolved in complex with substrates, an Fe(III)-nitrilotriacetate dimer or an Fe(III)-citrate trimer. The structural resolution of these UndA-Fe(III)-chelate complexes provides a rationale for previous kinetic measurements on UndA and other outer membrane cytochromes.},
doi = {10.1016/j.str.2012.04.016},
journal = {Structure},
number = 7,
volume = 20,
place = {United States},
year = {Tue Jul 03 00:00:00 EDT 2012},
month = {Tue Jul 03 00:00:00 EDT 2012}
}
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