Structural highlights
Publication Abstract from PubMed
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 has also been 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.
The Crystal Structure of the Extracellular 11-heme Cytochrome UndA Reveals a Conserved 10-heme Motif and Defined Binding Site for Soluble Iron Chelates.,Edwards MJ, Hall A, Shi L, Fredrickson JK, Zachara JM, Butt JN, Richardson DJ, Clarke TA Structure. 2012 Jul 3;20(7):1275-84. Epub 2012 Jun 7. PMID:22682743[1]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
References
- ↑ Edwards MJ, Hall A, Shi L, Fredrickson JK, Zachara JM, Butt JN, Richardson DJ, Clarke TA. The Crystal Structure of the Extracellular 11-heme Cytochrome UndA Reveals a Conserved 10-heme Motif and Defined Binding Site for Soluble Iron Chelates. Structure. 2012 Jul 3;20(7):1275-84. Epub 2012 Jun 7. PMID:22682743 doi:10.1016/j.str.2012.04.016
