Michael Widjaja 1 , Kate Louise Harvey 1 , Lisa Hagemann 2 , Iain James Berry 1 , Veronica Maria Jarocki 1 , Benjamin Bernard Armando Raymond 1 , Jessica Leigh Tacchi 1 , Anne Gründel 2 , Joel Ricky Steele 1 , Matthew Paul Padula 3 , Ian George Charles 4 , Roger Dumke 2 , Steven Philip Djordjevic , 1 , 3
11 September 2017
Many bacterial moonlighting proteins were originally described in medically, agriculturally, and commercially important members of the low G + C Firmicutes. We show Elongation factor Tu (Ef-Tu) moonlights on the surface of the human pathogens Staphylococcus aureus (Sa Ef-Tu) and Mycoplasma pneumoniae (Mpn Ef-Tu), and the porcine pathogen Mycoplasma hyopneumoniae (Mhp Ef-Tu). Ef-Tu is also a target of multiple processing events on the cell surface and these were characterised using an N-terminomics pipeline. Recombinant Mpn Ef-Tu bound strongly to a diverse range of host molecules, and when bound to plasminogen, was able to convert plasminogen to plasmin in the presence of plasminogen activators. Fragments of Ef-Tu retain binding capabilities to host proteins. Bioinformatics and structural modelling studies indicate that the accumulation of positively charged amino acids in short linear motifs (SLiMs), and protein processing promote multifunctional behaviour. Codon bias engendered by an A + T rich genome may influence how positively-charged residues accumulate in SLiMs.