Department of Biology, ComBo, Florence Computational Biology Group, Department of Biology, LEMM, Laboratory of Microbial and Molecular Evolution Florence, University of Florence, I-50019 Sesto F.no, Italy.|INRIA Rhône-Alpes, Villeurbanne Cedex, France, Université de Lyon, F-69000 Lyon, France, Dipartimento di Ingegneria dellInformazione, University of Florence, I-50139 Firenze, Italy.|EMBL-EBI - European Bioinformatics Institute, Wellcome Trust Genome Campus, Hinxton, CB10 1SD Cambridge, UK.|Dipartimento di Ingegneria dellInformazione e Scienze Matematiche, University of Siena, Siena I-53100, Italy.|INRIA Rhône-Alpes, Villeurbanne Cedex, France, Université de Lyon, F-69000 Lyon, France, Université Lyon 1, CNRS,UMR5558, 69622 Villeurbanne Cedex, France and.|Computer Laboratory, University of Cambridge, CB3 0FD Cambridge, UK.|Dipartimento di Ingegneria dellInformazione, University of Florence, I-50139 Firenze, Italy.|Department of Biology, ComBo, Florence Computational Biology Group, Department of Biology, LEMM, Laboratory of Microbial and Molecular Evolution Florence, University of Florence, I-50019 Sesto F.no, Italy.|Department of Biology, ComBo, Florence Computational Biology Group, Department of Biology, LEMM, Laboratory of Microbial and Molecular Evolution Florence, University of Florence, I-50019 Sesto F.no, Italy.