6ef8

Cryo-EM of the OmcS nanowires from Geobacter sulfurreducensCryo-EM of the OmcS nanowires from Geobacter sulfurreducens

6ef8, resolution 3.70Å

Structural highlights

6ef8 is a 7 chain structure with sequence from Geobacter sulfurreducens PCA. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance.
Method:	Electron Microscopy, Resolution 3.7Å
Ligands:
Experimental data:	Check
Resources:	FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT

Function

OMCS_GEOSL Plays an important role in extracellular electron transfer. Can transfer electrons to insoluble Fe(3+) oxides as well as other extracellular electron acceptors, including Mn(4+) oxide and humic substances (PubMed:16332857, PubMed:20400557, PubMed:21236241). Essential for direct interspecies electron transfer (DIET) in cocultures with G. metallireducens (PubMed:23377933).^[1] ^[2] ^[3] ^[4]

Publication Abstract from PubMed

Long-range (>10 mum) transport of electrons along networks of Geobacter sulfurreducens protein filaments, known as microbial nanowires, has been invoked to explain a wide range of globally important redox phenomena. These nanowires were previously thought to be type IV pili composed of PilA protein. Here, we report a 3.7 A resolution cryoelectron microscopy structure, which surprisingly reveals that, rather than PilA, G. sulfurreducens nanowires are assembled by micrometer-long polymerization of the hexaheme cytochrome OmcS, with hemes packed within approximately 3.5-6 A of each other. The inter-subunit interfaces show unique structural elements such as inter-subunit parallel-stacked hemes and axial coordination of heme by histidines from neighboring subunits. Wild-type OmcS filaments show 100-fold greater conductivity than other filaments from a DeltaomcS strain, highlighting the importance of OmcS to conductivity in these nanowires. This structure explains the remarkable capacity of soil bacteria to transport electrons to remote electron acceptors for respiration and energy sharing.

Structure of Microbial Nanowires Reveals Stacked Hemes that Transport Electrons over Micrometers.,Wang F, Gu Y, O'Brien JP, Yi SM, Yalcin SE, Srikanth V, Shen C, Vu D, Ing NL, Hochbaum AI, Egelman EH, Malvankar NS Cell. 2019 Apr 4;177(2):361-369.e10. doi: 10.1016/j.cell.2019.03.029. PMID:30951668^[5]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

References

↑ Mehta T, Coppi MV, Childers SE, Lovley DR. Outer membrane c-type cytochromes required for Fe(III) and Mn(IV) oxide reduction in Geobacter sulfurreducens. Appl Environ Microbiol. 2005 Dec;71(12):8634-41. doi:, 10.1128/AEM.71.12.8634-8641.2005. PMID:16332857 doi:http://dx.doi.org/10.1128/AEM.71.12.8634-8641.2005
↑ Leang C, Qian X, Mester T, Lovley DR. Alignment of the c-type cytochrome OmcS along pili of Geobacter sulfurreducens. Appl Environ Microbiol. 2010 Jun;76(12):4080-4. doi: 10.1128/AEM.00023-10. Epub, 2010 Apr 16. PMID:20400557 doi:http://dx.doi.org/10.1128/AEM.00023-10
↑ Qian X, Mester T, Morgado L, Arakawa T, Sharma ML, Inoue K, Joseph C, Salgueiro CA, Maroney MJ, Lovley DR. Biochemical characterization of purified OmcS, a c-type cytochrome required for insoluble Fe(III) reduction in Geobacter sulfurreducens. Biochim Biophys Acta. 2011 Apr;1807(4):404-12. doi: 10.1016/j.bbabio.2011.01.003., Epub 2011 Jan 12. PMID:21236241 doi:http://dx.doi.org/10.1016/j.bbabio.2011.01.003
↑ Shrestha PM, Rotaru AE, Summers ZM, Shrestha M, Liu F, Lovley DR. Transcriptomic and genetic analysis of direct interspecies electron transfer. Appl Environ Microbiol. 2013 Apr;79(7):2397-404. doi: 10.1128/AEM.03837-12. Epub , 2013 Feb 1. PMID:23377933 doi:http://dx.doi.org/10.1128/AEM.03837-12
↑ Wang F, Gu Y, O'Brien JP, Yi SM, Yalcin SE, Srikanth V, Shen C, Vu D, Ing NL, Hochbaum AI, Egelman EH, Malvankar NS. Structure of Microbial Nanowires Reveals Stacked Hemes that Transport Electrons over Micrometers. Cell. 2019 Apr 4;177(2):361-369.e10. doi: 10.1016/j.cell.2019.03.029. PMID:30951668 doi:http://dx.doi.org/10.1016/j.cell.2019.03.029

Proteopedia Page Contributors and Editors (what is this?)Proteopedia Page Contributors and Editors (what is this?)

OCA

[1] Mehta T, Coppi MV, Childers SE, Lovley DR. Outer membrane c-type cytochromes required for Fe(III) and Mn(IV) oxide reduction in Geobacter sulfurreducens. Appl Environ Microbiol. 2005 Dec;71(12):8634-41. doi:, 10.1128/AEM.71.12.8634-8641.2005. PMID:16332857 doi:http://dx.doi.org/10.1128/AEM.71.12.8634-8641.2005

[2] Leang C, Qian X, Mester T, Lovley DR. Alignment of the c-type cytochrome OmcS along pili of Geobacter sulfurreducens. Appl Environ Microbiol. 2010 Jun;76(12):4080-4. doi: 10.1128/AEM.00023-10. Epub, 2010 Apr 16. PMID:20400557 doi:http://dx.doi.org/10.1128/AEM.00023-10

[3] Qian X, Mester T, Morgado L, Arakawa T, Sharma ML, Inoue K, Joseph C, Salgueiro CA, Maroney MJ, Lovley DR. Biochemical characterization of purified OmcS, a c-type cytochrome required for insoluble Fe(III) reduction in Geobacter sulfurreducens. Biochim Biophys Acta. 2011 Apr;1807(4):404-12. doi: 10.1016/j.bbabio.2011.01.003., Epub 2011 Jan 12. PMID:21236241 doi:http://dx.doi.org/10.1016/j.bbabio.2011.01.003

[4] Shrestha PM, Rotaru AE, Summers ZM, Shrestha M, Liu F, Lovley DR. Transcriptomic and genetic analysis of direct interspecies electron transfer. Appl Environ Microbiol. 2013 Apr;79(7):2397-404. doi: 10.1128/AEM.03837-12. Epub , 2013 Feb 1. PMID:23377933 doi:http://dx.doi.org/10.1128/AEM.03837-12

[5] Wang F, Gu Y, O'Brien JP, Yi SM, Yalcin SE, Srikanth V, Shen C, Vu D, Ing NL, Hochbaum AI, Egelman EH, Malvankar NS. Structure of Microbial Nanowires Reveals Stacked Hemes that Transport Electrons over Micrometers. Cell. 2019 Apr 4;177(2):361-369.e10. doi: 10.1016/j.cell.2019.03.029. PMID:30951668 doi:http://dx.doi.org/10.1016/j.cell.2019.03.029

[1]

[2]

[3]

[4]

[5]