Adenosine Triphosphatases/chemistry; Bacterial Proteins/chemistry; Escherichia coli Proteins/chemistry; Membrane Transport Proteins/chemistry; Receptors, Cytoplasmic and Nuclear/chemistry; Receptors, Peptide/chemistry; Ribosomes/chemistry; Signal Recognition Particle/chemistry; Adenosine Triphosphatases/metabolism; Bacterial Proteins/genetics; Bacterial Proteins/metabolism; Binding Sites; Escherichia coli/cytology; Escherichia coli/metabolism; Escherichia coli Proteins/genetics; Escherichia coli Proteins/metabolism; Fluorescence Resonance Energy Transfer; Humans; Mass Spectrometry; Membrane Transport Proteins/metabolism; Models, Molecular; Protein Binding; Protein Structure, Tertiary; Protein Subunits/chemistry; Protein Subunits/genetics; Protein Subunits/metabolism; Receptors, Cytoplasmic and Nuclear/genetics; Receptors, Cytoplasmic and Nuclear/metabolism; Receptors, Peptide/genetics; Receptors, Peptide/metabolism; Ribosomes/metabolism; SEC Translocation Channels; SecA Proteins; Signal Recognition Particle/metabolism