1. Institute of Bioinformatics, University of Georgia, Athens, GA 30602, USA.
2. Department of Biochemistry and Molecular Biology, University of Georgia, Athens, GA 30602, USA.
3. Department of Genetics, University of Georgia, Athens, GA 30602, USA.
4. Department of Computer Science, University of Georgia, Athens, GA 30602, USA.
5. Department of Biochemistry, Institute of Integrative Biology, University of Liverpool, Liverpool L69 7ZB, UK.