User:Nikhil Malvankar/Geobacter pilus structure and function
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Our electron cryomicroscopic structure of ''Geobacter sulfurreducens'' pili, [[6vk9]], reveals them to be composed of a core of '''<font color='#e87000'>PilA-N</font>''' coated with an outer surface layer of '''<font color='00a0a0'>PilA-C</font>''' (104 amino acids; <scene name='83/834714/Filament/1'>restore initial scene)</scene>. Here is a <scene name='83/834714/Filament/2'>cutaway view</scene> (front half hidden). The C-termini of '''<font color='#e87000'>PilA-N</font>''' <scene name='83/834714/Filament/3'>protrude into sockets</scene> in '''<font color='00a0a0'>PilA-C</font>'''. | Our electron cryomicroscopic structure of ''Geobacter sulfurreducens'' pili, [[6vk9]], reveals them to be composed of a core of '''<font color='#e87000'>PilA-N</font>''' coated with an outer surface layer of '''<font color='00a0a0'>PilA-C</font>''' (104 amino acids; <scene name='83/834714/Filament/1'>restore initial scene)</scene>. Here is a <scene name='83/834714/Filament/2'>cutaway view</scene> (front half hidden). The C-termini of '''<font color='#e87000'>PilA-N</font>''' <scene name='83/834714/Filament/3'>protrude into sockets</scene> in '''<font color='00a0a0'>PilA-C</font>'''. | ||
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| + | The '''<font color='#e87000'>PilA-N</font>''' subunits have extensive hydrophobic contacts with each other, stabilizing the hydrophobic core of the filament. Each '''<font color='#e87000'>PilA-N</font>''' chain contacts 75 carbon atoms from contacting '''<font color='#e87000'>PilA-N</font>''' chains, and also has 4 hydrogen bonds and 4 salt bridges with contacting '''<font color='#e87000'>PilA-N</font>''' chains. In contrast, '''<font color='00a0a0'>PilA-C</font>''' subunits have little contact with each other: 14 atoms, which are mostly hydrogen bonds with one salt bridge. <font color="red">[Scenes not yet constructed.]</font> | ||
The filament is assembled from <scene name='83/834714/Dimer/3'>heterodimers</scene>. Dimer <scene name='83/834714/Dimer/2'>secondary structure</scene>: '''<font color='#e87000'>PilA-N</font>''' consists of two alpha helices, while '''<font color='00a0a0'>PilA-C</font>''' includes a 3-stranded beta sheet. The C-terminal protrusion of '''<font color='#e87000'>PilA-N</font>''' is <scene name='83/834714/Flaps/4'>held between two flaps</scene> (darker) of '''<font color='00a0a0'>PilA-C</font>'''. The flaps have almost no contact with each other. They are held in place by apolar contacts and hydrogen bonds with the C-terminal protrusion of '''<font color='#e87000'>PilA-N</font>'''. These flaps might be open before '''<font color='#e87000'>PilA-N</font>''' arrives to form a dimer, reminiscent of the flaps of HIV protease<ref>PMID: 16418268</ref>. (See, for example, [[1hxw]].) | The filament is assembled from <scene name='83/834714/Dimer/3'>heterodimers</scene>. Dimer <scene name='83/834714/Dimer/2'>secondary structure</scene>: '''<font color='#e87000'>PilA-N</font>''' consists of two alpha helices, while '''<font color='00a0a0'>PilA-C</font>''' includes a 3-stranded beta sheet. The C-terminal protrusion of '''<font color='#e87000'>PilA-N</font>''' is <scene name='83/834714/Flaps/4'>held between two flaps</scene> (darker) of '''<font color='00a0a0'>PilA-C</font>'''. The flaps have almost no contact with each other. They are held in place by apolar contacts and hydrogen bonds with the C-terminal protrusion of '''<font color='#e87000'>PilA-N</font>'''. These flaps might be open before '''<font color='#e87000'>PilA-N</font>''' arrives to form a dimer, reminiscent of the flaps of HIV protease<ref>PMID: 16418268</ref>. (See, for example, [[1hxw]].) | ||
Revision as of 02:08, 9 February 2020
Interactive 3D Complement in Proteopedia
Structure of novel pili evolved for extracellular translocation of microbial nanowires.
Yangqi Gu,
Vishok Srikanth,
Ruchi Jain,
Aldo I. Salazar-Morales,
J. Patrick O'Brien,
Sophia M. Yi,
Rajesh K. Soni,
Fadel A. Samatey,
Sibel Ebru Yalcin,
and Nikhil S. Malvankar.
(journal article link here) (2020).
(DOI link here)
Contents |
Molecular Tour
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Download
Animations for Powerpoint
Click images to see them full size, or to download them.
- (to be added)
See Also
- (to be added)
Notes & References
- ↑ Malvankar NS, Vargas M, Nevin K, Tremblay PL, Evans-Lutterodt K, Nykypanchuk D, Martz E, Tuominen MT, Lovley DR. Structural basis for metallic-like conductivity in microbial nanowires. MBio. 2015 Mar 3;6(2):e00084. doi: 10.1128/mBio.00084-15. PMID:25736881 doi:http://dx.doi.org/10.1128/mBio.00084-15
- ↑ Lovley DR, Walker DJF. Geobacter Protein Nanowires. Front Microbiol. 2019 Sep 24;10:2078. doi: 10.3389/fmicb.2019.02078. eCollection , 2019. PMID:31608018 doi:http://dx.doi.org/10.3389/fmicb.2019.02078
- ↑ 3.0 3.1 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
- ↑ 4.0 4.1 Filman DJ, Marino SF, Ward JE, Yang L, Mester Z, Bullitt E, Lovley DR, Strauss M. Cryo-EM reveals the structural basis of long-range electron transport in a cytochrome-based bacterial nanowire. Commun Biol. 2019 Jun 19;2(1):219. doi: 10.1038/s42003-019-0448-9. PMID:31925024 doi:http://dx.doi.org/10.1038/s42003-019-0448-9
- ↑ Hornak V, Okur A, Rizzo RC, Simmerling C. HIV-1 protease flaps spontaneously open and reclose in molecular dynamics simulations. Proc Natl Acad Sci U S A. 2006 Jan 24;103(4):915-20. doi:, 10.1073/pnas.0508452103. Epub 2006 Jan 17. PMID:16418268 doi:http://dx.doi.org/10.1073/pnas.0508452103
