View Full Version : Cell membrane proteins and TMPred plot
Gernald
Oct 24, 2009, 09:23 AM
How do you read a TMPred plot? I need to figure out what type of membrane protein it could be.
Soooo confused!
Thanks for the help!:eek:
asking
Oct 24, 2009, 03:47 PM
I don't even know what TMPred is.
You know who might know is templelane. You might pm her.
Good luck!
jem02081
Oct 24, 2009, 04:59 PM
I have looked at these plots before, but I’m not an expert at this.
This is a plot of predicted membrane spanning regions in a protein. The x-axis in the amino position (N term = 1) in the protein & the Y-axis is the score. Score >500 are considered “positive” but the program does detect “false positive” membrane spanning domains. The I->o plot is the inside to outside plot prediction & o->I is the outside to inside plot. I would be skeptical of this unless your protein is homologous to a protein in the database.
In summary “The TMpred program makes a prediction of membrane-spanning regions and their orientation. The algorithm is based on the statistical analysis of TMbase, a database of naturally occuring transmembrane proteins. The prediction is made using a combination of several weight-matrices for scoring.” From TMpred Server (http://www.ch.embnet.org/software/TMPRED_form.html)
If I were to guess it looks like it could be a 7 membrane spanning (= trans membrane = TM) G protein-coupled receptor (GPCR).
You could convince yourself be plotting some 7TM GPCRs or looking to see what proteins (or protein domains this sequence is similar to). Try PredictProtein - Structure Prediction and Sequence Analysis (http://www.predictprotein.org/)
Unknown008
Oct 25, 2009, 12:32 AM
I don't even know what TMPred is.
You know who might know is templelane. You might pm her.
Good luck!
Ah, it's been a long time since I didn't see her on here!
asking
Oct 25, 2009, 08:37 PM
It has been a while. I wonder what she's up to...