1. Instituto de Biología Molecular ‘Eladio Viñuela’ (CSIC), Centro de Biología Molecular ‘Severo Ochoa’ (CSIC-Universidad Autónoma de Madrid), Cantoblanco, 28049 Madrid, Spain
2. Institute of Microbiology and Infection, School of Biosciences, University of Birmingham, Birmingham B15 2TT, UK
3. Department of Biology, Biotechnical Faculty, University of Ljubljana, 1000 Ljubljana, Slovenia