1. Garnier-Osguthorpe-Robson
GOR Method

2. Article
Analysis of the Accuracy and Implications of Simple Methods for Predicting the Secondary Structure of Globular Proteins
J. Garnier, D.J. Osguthorpe and B Robson
Journal of Molecular Biology (1978); 120,

3. Introduction Predict secondary structure from aa-sequence alone
Simple predictive algorithm
Four-state predictions
More additional information enhances prediction

4. Theory Predict conformational state of each residue in a sequence
I(Sj; R1, R2, … Rlast)
Effect of one residue affects conformation up to eight residues distant
20 X 4 X 17 parameters

5. Method Each amino acid is predicted to exist in one of four states:
1) H = helix
2) C = coil
3) T = turn
4) E = extended chain (beta-strand)
Each residue is given a score based upon the nature and positions of the ± 8th residues according to previously calculated tables.
The residue receives a score for each of the conformational possibilities and the highest one gives the prediction.

6. Example
Arg-Gly-Ser-Ala-Lys-Cys-Trp-Tyr-Pro-Ala-Val-Gly-Glu-Lys-Asp-Met-Ile
The Pro residue would receive the following scores based on the previously calculated tables:

7. Advantages/Disadvantages
Better predictions
Long-range interactions
5 to 10% improvement with homology studies
Only 63% correct
Depends on database
the GOR method is an approximation