Green Fluorescent Protein: Difference between revisions

From Proteopedia
Jump to navigationJump to search
← Older editNewer edit →
Joel L. Sussman (talk | contribs)
ConfirmAccount, Editor, Mutation, Print3D, Tester, Bureaucrats, journal
11,708 edits
No edit summary
Eran Hodis (talk | contribs)
7,087 edits
Line 18: Line 18:
{{STRUCTURE_1ema |  SIZE=500 |PDB=1ema  |  SCENE=Green_Fluorescent_Protein/1ema_gfp_default/2 |CAPTION = 1ema, resolution 1.90&Aring; (<scene name='Green_Fluorescent_Protein/1ema_gfp_default/2'>default scene</scene>).}}
{{STRUCTURE_1ema |  SIZE=500 |PDB=1ema  |  SCENE=Green_Fluorescent_Protein/1ema_gfp_default/2 |CAPTION = 1ema, resolution 1.90&Aring; (<scene name='Green_Fluorescent_Protein/1ema_gfp_default/2'>default scene</scene>).}}
Green fluorescent protein (<scene name='Green_Fluorescent_Protein/1ema_gfp_default/2'>default scene</scene>) is a 21 kDa protein consisting of 238 residues strung together to form a   
Green fluorescent protein (<scene name='Green_Fluorescent_Protein/1ema_gfp_default/2'>default scene</scene>) is a 21 kDa protein consisting of 238 residues strung together to form a   
<scene name='Green_Fluorescent_Protein/1ema_gfp_barrel/2'>secondary structure</scene> of five α-helices and one eleven-stranded β-pleated sheet,<ref name="PDBsum" /> where each strand contains nine to thirteen residues each.<ref name="Ormo" />  (To view the primary and secondary structure of GFP, go to [[http://www.ebi.ac.uk/thornton-srv/databases/cgi-bin/pdbsum/GetPage.pl?pdbcode=1ema&template=protein.html&r=wiring&l=1&chain=A www.ebi.aci.uk]].)  These β-strands display an almost “seamless symmetry” in which only two of the strands vary in structural content.<ref name="Phillips">PMID: 9434902</ref>  This β-sheet conforms itself through regular hydrogen bonding into a β-barrel.<ref name="Yang" />  In GFP, the structure is so regular that <scene name='Green_Fluorescent_Protein/Water_stripes/1'>"stripes"</scene> of water molecules (red) can be seen following the structure of the barrel.<ref name="Phillips" />  Together with the α-helices at either end of the molecule, a nearly perfect cylinder is produced, 42Å long and 24Å in diameter,<ref name="Ormo" /> creating what is referred to as a “β-can” formation.<ref name="Phillips" />  The short helical segments at either end of the cylinder form “caps” to further protect the interior of the β-barrel.<ref name="Phillips" />  Overall stability is maintained by this β-can structure, helping to resist unfolding from heat and other denaturants.<ref name="Yang" />
<scene name='Green_Fluorescent_Protein/1ema_gfp_barrel/2'>secondary structure</scene> of five α-helices and one eleven-stranded β-pleated sheet,<ref name="PDBsum" /> where each strand contains nine to thirteen residues each.<ref name="Ormo" />  (To view the primary and secondary structure of GFP, go to [http://www.ebi.ac.uk/thornton-srv/databases/cgi-bin/pdbsum/GetPage.pl?pdbcode=1ema&template=protein.html&r=wiring&l=1&chain=A www.ebi.aci.uk].)  These β-strands display an almost “seamless symmetry” in which only two of the strands vary in structural content.<ref name="Phillips">PMID: 9434902</ref>  This β-sheet conforms itself through regular hydrogen bonding into a β-barrel.<ref name="Yang" />  In GFP, the structure is so regular that <scene name='Green_Fluorescent_Protein/Water_stripes/1'>"stripes"</scene> of water molecules (red) can be seen following the structure of the barrel.<ref name="Phillips" />  Together with the α-helices at either end of the molecule, a nearly perfect cylinder is produced, 42Å long and 24Å in diameter,<ref name="Ormo" /> creating what is referred to as a “β-can” formation.<ref name="Phillips" />  The short helical segments at either end of the cylinder form “caps” to further protect the interior of the β-barrel.<ref name="Phillips" />  Overall stability is maintained by this β-can structure, helping to resist unfolding from heat and other denaturants.<ref name="Yang" />


One <scene name='Green_Fluorescent_Protein/Central_helix/1'>α-helix</scene> can be found running through the central axis of the β-barrel,<ref name="Haldar" /> roughly <scene name='Green_Fluorescent_Protein/Perpendicular/1'>perpendicular</scene> to the symmetry axis of the barrel.<ref name="Ormo">Ormo M, Cubitt AB, Kallio K, Gross LA, Tsien RY, Remington SJ.  1996.  Crystal structure of the ''Aequorea victoria'' green fluorescent protein.  Science.  273(5280):1392-1395.  DOI 10.1126/science.273.5280.1392.</ref>  This helix is extremely important as it contains the fluorophore responsible for fluorescence.<ref name="Yang" /><ref name="Haldar" />  This α-helix in particular is highly stabilized by the many <scene name='Green_Fluorescent_Protein/Spacefill/1'>contacts</scene> that are made with each strand of the barrel.<ref name="Andrews">PMID:18713871</ref>
One <scene name='Green_Fluorescent_Protein/Central_helix/1'>α-helix</scene> can be found running through the central axis of the β-barrel,<ref name="Haldar" /> roughly <scene name='Green_Fluorescent_Protein/Perpendicular/1'>perpendicular</scene> to the symmetry axis of the barrel.<ref name="Ormo">Ormo M, Cubitt AB, Kallio K, Gross LA, Tsien RY, Remington SJ.  1996.  Crystal structure of the ''Aequorea victoria'' green fluorescent protein.  Science.  273(5280):1392-1395.  DOI 10.1126/science.273.5280.1392.</ref>  This helix is extremely important as it contains the fluorophore responsible for fluorescence.<ref name="Yang" /><ref name="Haldar" />  This α-helix in particular is highly stabilized by the many <scene name='Green_Fluorescent_Protein/Spacefill/1'>contacts</scene> that are made with each strand of the barrel.<ref name="Andrews">PMID:18713871</ref>
Retrieved from "https://proteopedia.org/Green_Fluorescent_Protein"