Assembly of Tat-dependent [NiFe] hydrogenases: identification of precursor-binding accessory proteins.
The Escherichia coli twin-arginine translocation (Tat) system serves to export fully folded protein substrates across the bacterial cytoplasmic membrane. Respiratory [NiFe] hydrogenases are synthesised as precursors with twin-arginine signal peptides and transported as large, cofactor-containing, multi-subunit complexes by the Tat system. Cofactor insertion and assembly of [NiFe] hydrogenases requires coordination of networks of accessory proteins. In this work we utilise a bacterial two-hybrid assay to demonstrate protein-protein interactions between the uncharacterised chaperones HyaE and HybE with Tat signal peptide-bearing hydrogenase precursors. It is proposed that the chaperones act at a 'proofreading' stage in hydrogenase assembly and police the protein transport pathway preventing premature targeting of Tat-dependent hydrogenases.
Dubini
Alexandra
A
Centre for Metalloprotein Spectroscopy and Biology, School of Biological Sciences, University of East Anglia, Norwich NR4 7TJ, UK.
Sargent
Frank
F
D029968:Escherichia coli Proteins / Q000502:physiology*; D006864:Hydrogenase / Q000096:biosynthesis* / Q000378:metabolism; D026901:Membrane Transport Proteins / Q000502:physiology*; D018832:Molecular Chaperones / Q000502:physiology; D011485:Protein Binding; D011498:Protein Precursors / Q000378:metabolism*; D021382:Protein Sorting Signals; D021381:Protein Transport; D020239:Receptor Cross-Talk; D020798:Two-Hybrid System Techniques
D029968:Escherichia coli Proteins; D026901:Membrane Transport Proteins; D018832:Molecular Chaperones; D011498:Protein Precursors; D021382:Protein Sorting Signals; C408585:twin-arginine translocase complex, E coli; C043296:nickel-iron hydrogenase; D006864:Hydrogenase