EF-Tu is a monomeric protein with molecular weight around 43 kDa in Escherichia coli.
 The protein consists of three structural domains: a GTP-binding domain and two oligonucleotide-binding domains, often referred to as domain 2 and domain 3.
 The N-terminal domain I of EF-Tu is the GTP-binding domain.
 It consists of a six beta-strand core flanked by six alpha-helices.
 Domains II and III of EF-Tu, the oligonucleotide-binding domains, both adopt beta-barrel structures.

The GTP-binding domain I undergoes a dramatic conformational change upon GTP hydrolysis to GDP, allowing EF-Tu to dissociate from aa-tRNA and leave the ribosome.
 Reactivation of EF-Tu is achieved by GTP binding in the cytoplasm, which leads to a significant conformational change that reactivates the tRNA-binding site of EF-Tu.
 In particular, GTP binding to EF-Tu results in a ~90° rotation of domain I relative to domains II and III, exposing the residues of the tRNA-binding active site.

Domain 2 adopts a beta-barrel structure, and is involved in binding to charged tRNA.
This domain is structurally related to the C-terminal domain of EF2, to which it displays weak sequence similarity.
This domain is also found in other proteins such as translation initiation factor IF-2 and tetracycline-resistance proteins.
Domain 3 represents the C-terminal domain, which adopts a beta-barrel structure, and is involved in binding to both charged tRNA and to EF1B (or EF-Ts).
EF-Tu is a monomeric protein with molecular weight around 43 kDa in Escherichia coli.  The protein consists of three structural domains: a GTP-binding domain and two oligonucleotide-binding domains, often referred to as domain 2 and domain 3.  The N-terminal domain I of EF-Tu is the GTP-binding domain.  It consists of a six beta-strand core flanked by six alpha-helices.  Domains II and III of EF-Tu, the oligonucleotide-binding domains, both adopt beta-barrel structures.
The GTP-binding domain I undergoes a dramatic conformational change upon GTP hydrolysis to GDP, allowing EF-Tu to dissociate from aa-tRNA and leave the ribosome.  Reactivation of EF-Tu is achieved by GTP binding in the cytoplasm, which leads to a significant conformational change that reactivates the tRNA-binding site of EF-Tu.  In particular, GTP binding to EF-Tu results in a ~90° rotation of domain I relative to domains II and III, exposing the residues of the tRNA-binding active site.
Domain 2 adopts a beta-barrel structure, and is involved in binding to charged tRNA. This domain is structurally related to the C-terminal domain of EF2, to which it displays weak sequence similarity. This domain is also found in other proteins such as translation initiation factor IF-2 and tetracycline-resistance proteins. Domain 3 represents the C-terminal domain, which adopts a beta-barrel structure, and is involved in binding to both charged tRNA and to EF1B (or EF-Ts).
EF-Tu