High resolution crystal structure of bovine mitochondrial EF-Tu in complexwith GDP

The crystal structure of bovine mitochondrial elongation factor Tu (EF-Tu) in complex with GDP has been determined at a resolution of 1.94 Angstrom. T he structure is similar to that of EF-Tu:GDP from Escherichia coli and Ther mus aquaticus, but the orientation of the CDP-binding domain 1 is changed r elative to domains 2 and 3. Sixteen conserved water molecules common to EF- Tu and other G-proteins in the GDP-binding site are described. These water molecules create a network linking separated parts of the binding pocket. M itochondrial EF-Tu binds nucleotides less tightly than prokaryotic EF-Tu po ssibly due to an increased mobility in regions close to the GDP-binding sit e. The C-terminal extension of mitochondrial EF-Tu has structural similarit ies with DNA recognising zinc fingers suggesting that the extension may be involved in recognition of RNA. (C) 2000 Academic Press.