XtalPred is a crystallisation prediction server (link to server homepage). For a given protein sequence, the server predicts the likelihood that the sequence can be crystallised in the form of an integer from 1 to 5 (1 is the most likely to crystallise and 5 is the least likely to crystallise).
For more information on XtalPred visit the XtalPred Server: About section
Each individual feature is converted into a crystallisation probability based on a benchmark testset of proteins worked on by Structural Genomics (SG) centres. The testset contained a total of 3959 proteins (1503 positive subset, 2456 negative subset).
The crystallisation probabilities are combined to give a crystallisation feasibility score using a logarithmic opinion pool approach. Based on this score the sequence is assigned to a crystallisation class from 1 to 5. The class reflects the decreasing crystallization success rates observed from ranking the testset by the feasibility score and dividing the list into five equal parts.
Crystallisation Success Rates
From Slabinski et al, Protein Science, 2007, Figure 4B
The XtalPred server -
Slabinski, L., Jaroszewski, L., Rychlewski, L., Wilson, I.A., Lesley, S.A., Godzik, A. XtalPred: a web server for prediction of protein crystallizability. Bioinformatics, 2007 23(24):3403-5.
PMID: 17921170 link to PubMed
The method -
Slabinski, L., Jaroszewski, L., Rodrigues, A.P.C., Rychlewski, L., Wilson, I.A., Lesley, S.A., Godzik, A. The challenge of protein structure determination - lessons from structural genomics. Protein Science, 2007 16(11):2472-82.
PMID: 17962404 link to PubMed