Function of initiation factor 1 in the binding and release of initiation factor 2 from ribosomal initiation complexes in Escherichia coli.

Protein Disorder Is Positively Correlated with Gene Expression in Escherichia coli

“…IF1 is a highly conserved element of the prokaryotic translational apparatus and has also been found in the chloroplasts of plants. Several functions have been reported for IF1, including the enhancement of the rate of 70S ribosome dissociation and subunit association, the stimulation of the activity of initiation factors IF2 and IF3 in the formation of the 30S initiation complex, and the modulation of the interaction of IF2 with the ribosome . NMR analysis revealed that IF1 is an ordered protein consisting of a five-stranded β-sheet, arranged as a β-barrel .…”

“…Several functions have been reported for IF1, including the enhancement of the rate of 70S ribosome dissociation and subunit association, 66 the stimulation of the activity of initiation factors IF2 and IF3 in the formation of the 30S initiation complex, 67 and the modulation of the interaction of IF2 with the ribosome. 68 NMR analysis revealed that IF1 is an ordered protein consisting of a five-stranded β-sheet, arranged as a β-barrel. 69 While the turns connecting strands I and II and strands II and III are well-defined, the region connecting strands III and IV (residues 37-49) and the short loop con- necting strands IV and V (residues 57-62) have considerable flexibility on the nanosecond time scale.…”

Kinetic Dissection of Translation Initiation in Prokaryotes.

“…IF1 stimulates IF2 binding to the ribosome (Caserta et al, 2006;Celano et al, 1988;Gualerzi and Pon, 1990;Milón et al, 2012a;Moreno et al, 1999;Stringer et al, 1977;Weiel and Hershey, 1982). IF1 interacts with IF2 on the ribosome (Allen et al, 2005;Boileau et al, 1983;Brock et al, 1998) which is probably how stabilization of IF2 on the ribosome is achieved; the reverse effect is also true -IF1 was shown to be stabilized on the ribosome in the presence of IF2 (Caserta et al, 2006;Celano et al, 1988;Milón et al, 2012a;Stringer et al, 1977;Weiel and Hershey, 1982). The interaction between IF1 and IF2 was suggested to be universal as similar interaction is observed also in the eukaryotic system (Chaudhuri et al, 1997;Roll-Mecak et al, 2000).…”

“…One of the proposed functions of IF1 in translation initiation is stimulation of the action of the other initiation factors IF2 and IF3 (Antoun et al, 2006a;Laursen et al, 2005;Pon and Gualerzi, 1984;Wintermeyer and Gualerzi, 1983). IF1 stimulates IF2 binding to the ribosome (Caserta et al, 2006;Celano et al, 1988;Gualerzi and Pon, 1990;Milón et al, 2012a;Moreno et al, 1999;Stringer et al, 1977;Weiel and Hershey, 1982). IF1 interacts with IF2 on the ribosome (Allen et al, 2005;Boileau et al, 1983;Brock et al, 1998) which is probably how stabilization of IF2 on the ribosome is achieved; the reverse effect is also true -IF1 was shown to be stabilized on the ribosome in the presence of IF2 (Caserta et al, 2006;Celano et al, 1988;Milón et al, 2012a;Stringer et al, 1977;Weiel and Hershey, 1982).…”

“…Recycling of IF2 on/off 70S is also effected by IF1 as it alters the thermodynamic stability of the IF2-30S complex (Chae et al, 1969;Kay and Grunberg-Manago, 1972;Stringer et al, 1977;Voorma et al, 1979).…”