Journal:Acta Cryst D:S2059798319009008
From Proteopedia
(Difference between revisions)
| (3 intermediate revisions not shown.) | |||
| Line 4: | Line 4: | ||
<hr/> | <hr/> | ||
<b>Molecular Tour</b><br> | <b>Molecular Tour</b><br> | ||
| - | Solving a protein crystal structure without a homologous template involves experimental phasing. Ultimately, this requires the incorporation of heavy atoms into the lattice of the protein crystal. However, this process can be very laborious as suitable heavy atom compounds and conditions are found empirically through screening. A method to efficiently derivatize crystals was developed, by performing a Random Microseed Matrix screen (rMMS) in the presence of I3C. | + | Solving a protein crystal structure without a homologous template involves experimental phasing. Ultimately, this requires the incorporation of heavy atoms into the lattice of the protein crystal. However, this process can be very laborious as suitable heavy atom compounds and conditions are found empirically through screening. A method to efficiently derivatize crystals was developed, by performing a Random Microseed Matrix screen (rMMS) in the presence of 5-amino-2,4,6-triiodoisophthalic acid (I3C). |
| - | In a random microseed matrix, a crystal or crystalline precipitate is crushed up, diluted and added to new crystallization conditions from a sparse matrix screen. This often generates new crystallization where crystals can grow. I3C | + | In a random microseed matrix, a crystal or crystalline precipitate is crushed up, diluted and added to new crystallization conditions from a sparse matrix screen. This often generates new crystallization where crystals can grow. I3C is compatible with many crystallization reagents and provides a large phasing power. |
| - | In the two test proteins, the <scene name='81/819238/Cv/2'>Orf11 NTD</scene> from ''Staphylococcus'' phage P68 and <scene name='81/819238/Cv/3'>Hen Egg White Lysozyme</scene>, the rMMS technique in the presence of I3C generated numerous new conditions where derivatized crystals could grow. The I3C molecules in the lattice were sufficient to completely solve the structure using anomalous phasing methods. | + | In the two test proteins, the <scene name='81/819238/Cv/2'>Orf11 NTD</scene> from ''Staphylococcus'' phage P68 (PDB entry [[6o43]]) and <scene name='81/819238/Cv/3'>Hen Egg White Lysozyme</scene> (PDB entry [[6pbb]]), the rMMS technique in the presence of I3C generated numerous new conditions where derivatized crystals could grow. The I3C molecules in the lattice were sufficient to completely solve the structure using anomalous phasing methods. |
I3C was present in the tested crystals in the rMMS screens containing I3C, where they often sit at the junctions between protein molecules in the lattice. These bridging contacts could improve the crystal lattice or generate new conditions where crystals can grow. | I3C was present in the tested crystals in the rMMS screens containing I3C, where they often sit at the junctions between protein molecules in the lattice. These bridging contacts could improve the crystal lattice or generate new conditions where crystals can grow. | ||
| Line 15: | Line 15: | ||
*<scene name='81/819238/Cv/9'>One I3C molecule from the lysozyme crystal</scene>. | *<scene name='81/819238/Cv/9'>One I3C molecule from the lysozyme crystal</scene>. | ||
*<scene name='81/819238/Cv/14'>I3C molecule from Orf11 NTD crystal (1st orientation)</scene>. | *<scene name='81/819238/Cv/14'>I3C molecule from Orf11 NTD crystal (1st orientation)</scene>. | ||
| + | *<scene name='81/819238/Cv/16'>I3C molecule from Orf11 NTD crystal (2nd orientation)</scene>. | ||
The same I3C molecule from the Orf11 NTD crystal is displayed in two different orientations for clarity. I3C-protein interactions include hydrogen bonding, π-π stacking interactions, salt bridges, water bridges and halogen bonding. In both cases, each I3C molecule forms interactions with three different proteins molecules (each shown in a different color), which could assist in lattice packing. | The same I3C molecule from the Orf11 NTD crystal is displayed in two different orientations for clarity. I3C-protein interactions include hydrogen bonding, π-π stacking interactions, salt bridges, water bridges and halogen bonding. In both cases, each I3C molecule forms interactions with three different proteins molecules (each shown in a different color), which could assist in lattice packing. | ||
| + | |||
| + | '''PDB references:''' Crystal structure of a lysin protein from Staphylococcus phage P68 [[6o43]]; Crystal structure of Hen Egg White Lysozyme in complex with I3C [[6pbb]]. | ||
<b>References</b><br> | <b>References</b><br> | ||
Current revision
| |||||||||||
Proteopedia Page Contributors and Editors (what is this?)
This page complements a publication in scientific journals and is one of the Proteopedia's Interactive 3D Complement pages. For aditional details please see I3DC.
