Jmol/Visualizing membrane position

Revision as of 22:22, 30 March 2018 by Eric Martz (talk | contribs)

Here are two ways of visualizing the position of a lipid bilayer membrane around the integral membrane portion of a trans-membrane protein.

Outside

Inside

1. represent the water-lipid boundaries. Red pseudoatoms represent the extracellular boundary, and blue pseudoatoms represent the cytoplasmic boundary.[1]


2. A represents membrane near the protein. If desired, .

a hydrophobic vs. polar color scheme, the protein within the lipid bilayer is seen to have a largely hydrophobic surface. The example used here is 5lil.

Methods: Pseudoatoms

Any protein structure that includes an integral membrane domain can have pseudoatoms added to the PDB file by the Orientations of Proteins in Membranes Server[1]. Structures in the Protein Data Bank are pre-processed; other structures may be uploaded to the server. The server removes hydrogen atoms from the model.

You can download the pseudoatom-enhanced PDB file from the server, and then upload it to Proteopedia for use in a Molecular Scene.

In the case of 5LiL, I had difficulty getting the pseudoatoms to show from a green link (even though they displayed in the SAT). In the PDB file, the pseudoatoms followed a MASTER record. I deleted the MASTER record and all CONECT records, and then I got the results shown above with File:5lil opm2.pdb.

Methods: Translucent Cylinder

Choose boundary residues

First you must choose residues or atoms in the model that are closest to the ends of the desired cylinder. If you wish, you can use a pseudoatom-enhanced model to assist.

Viewing the model in FirstGlance in Jmol, you can use Hydrophobic/Polar (Views tab) to visualize the domain with a hydrophobic surface. Touching or clicking on atoms at the domain boundaries will identify those amino acids. If you wish, you can center a particular residue, then zoom in, and see atomic detail with Vines/Sticks (Views tab).


Caption for this structure

Drag the structure with the mouse to rotate

ReferencesReferences

  1. 1.0 1.1 Lomize MA, Pogozheva ID, Joo H, Mosberg HI, Lomize AL. OPM database and PPM web server: resources for positioning of proteins in membranes. Nucleic Acids Res. 2012 Jan;40(Database issue):D370-6. doi: 10.1093/nar/gkr703., Epub 2011 Sep 2. PMID:21890895 doi:http://dx.doi.org/10.1093/nar/gkr703

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

Eric Martz, Kristen Procko