Structural information for explaining the molecular mechanism of protein biosynthesis.
Protein biosynthesis is controlled by a number of proteins external to the ribosome. Of these, extensive structural investigations have been performed on elongation factor-Tu and elongation factor-G. This now gives a rather complete structural picture of the functional cycle of elongation factor-Tu and especially of the elongation phase of protein biosynthesis. The discovery that three domains of elongation factor-G are structurally mimicking the amino-acylated tRNA in the ternary complex of elongation factor-Tu has been the basis of much discussion of the functional similarities and functional differences of elongation factor-Tu and elongation factor-G in their interactions with the ribosome. Elongation factor-G:GDP is now thought to leave the ribosome in a state ready for checking the codon-anticodon interaction of the aminoacyl-tRNA contained in the ternary complex of elongation factor-Tu. Elongation factor-G does this by mimicking the shape of the ternary complex. Other translation factors such as the initiation factor-2 and the release factor 1 or 2 are also thought to mimic tRNA. These observations raise questions concerning the possible evolution of G-proteins involved in protein biosynthesis.
Clark
B F
BF
Institute of Molecular and Structural Biology, University of Aarhus, Denmark.
Thirup
S
S
Kjeldgaard
M
M
Nyborg
J
J
D001426:Bacterial Proteins / Q000096:biosynthesis* / Q000737:chemistry*; D008958:Models, Molecular; D018716:Molecular Mimicry; D011487:Protein Conformation; D013329:Structure-Activity Relationship
D001426:Bacterial Proteins