Department of Molecular Biology and Biochemistry, University of Málaga, Boulevard Louis Pasteur, 29071, Málaga, Spain.|Department of Algebra, Geometry and Topology, University of Málaga, Boulevard Louis Pasteur, 29071, Málaga, Spain.|European Molecular Biology Laboratory, Meyerhofstrasse 1, 69117, Heidelberg, Germany.|Department of Molecular Biology and Biochemistry, University of Málaga, Boulevard Louis Pasteur, 29071, Málaga, Spain. ranea@uma.es.