3UFK

Crystal structure of UndA complexed with Iron Nitrilotriacetate

Summary for 3UFK

• Entry DOI: 10.2210/pdb3ufk/pdb
• Related: 3UCP 3UFH
• Descriptor: UndA, HEME C, CALCIUM ION, ... (9 entities in total)
• Functional Keywords: c-type cytochrome, electron transport, outer membrane, transport protein
• Biological source: Shewanella sp. HRCR_06
• Total number of polymer chains: 1
• Total formula weight: 100765.73

Authors

Edwards, M.J.,Clarke, T.A. (deposition date: 2011-11-01, release date: 2012-08-08, Last modification date: 2023-11-15)

Primary citation

Edwards, M.J.,Hall, A.,Shi, L.,Fredrickson, J.K.,Zachara, J.M.,Butt, J.N.,Richardson, D.J.,Clarke, T.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.
Structure, 20:1275-1284, 2012

PubMed 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 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.

PubMed: 22682743
DOI: 10.1016/j.str.2012.04.016

Experimental method

X-RAY DIFFRACTION (2.1 Å)