1. Faculty of Biology; University of Athens; Panepistimioupolis Athens 15784 Greece
2. Faculty of Pharmacy; University of Athens; Panepistimioupolis Athens 15771 Greece
3. Bioinformatics and Genomics Programme; Centre for Genomic Regulation (CRG); Dr. Aiguader, 88 Barcelona 08003 Spain
4. Department of Experimental and Health Sciences; Universitat Pompeu Fabra (UPF); Barcelona 08003 Spain
5. Institució Catalana de Recerca i Estudis Avançats (ICREA); Pg. Lluís Companys 23 Barcelona 08010 Spain
6. Department of Microbiology; Imperial College; London SW7 2AZ UK
7. Institut de Génétique et Microbiologie; Université Paris-Sud; France