A proteomic approach to unveil Protein translation machinery holding a key for transition of planktonic cells to biofilm state in Enterococcus faecalis


Asad U Khan

Enterococcus faecalis is a member of human gut microflora which causes nosocomial infection involving biofilm formation. We have generated Ethyl methyl sulfonate induced mutants defective in biofilm which were analysed using crystal violet assay, SEM and CLSM microscopy. AK-E12 was confirmed as biofilm efficient and AK-F6 as biofilm deficient mutants in this study. Growth curve pattern revealed AK-E12 was fast growing whereas, AK-F6 was found slow growing mutant. MALDI-TOF and 2D-Electrophorosis analysis revealed expression and suppression of many translation-elongation associated proteins in
mutants compared to wild type. Protein translation elongation factor G, translation elongation factor Tu and ribosomal subunit interface proteins were down expressed and UTP--glucose-1-phosphate uridylyl
transferase and Cell division protein divIVA were over-expressed in AK-E12 as compared to wild type whereas, in AK-F6, except 10 kDa chaperonin which was over-expressed other selected proteins were
found to be down regulated. RT-PCR confirmed proteomic data except for the translation elongation factor G which showed contradictory data of proteome expression in AK-E12. Protein-protein interaction
networks were constructed using STRING 10.0 which demonstrated strong connection of translationelongation proteins with other proteins. Hence, we conclude that translation elongation factors are important in transition of planktonic cells to biofilm cells in E. faecalis.