Cloned (Comment) | Organism |
---|---|
recombinant expression of His-tagged IF2 in Escherichia coli using the T5 expression system | Escherichia coli |
Localization | Comment | Organism | GeneOntology No. | Textmining |
---|---|---|---|---|
ribosome | - |
Escherichia coli | 5840 | - |
Metals/Ions | Comment | Organism | Structure |
---|---|---|---|
Mg2+ | required | Escherichia coli |
Natural Substrates | Organism | Comment (Nat. Sub.) | Natural Products | Comment (Nat. Pro.) | Rev. | Reac. |
---|---|---|---|---|---|---|
GTP + H2O | Escherichia coli | - |
GDP + phosphate | - |
? |
Organism | UniProt | Comment | Textmining |
---|---|---|---|
Escherichia coli | P0A705 | - |
- |
Purification (Comment) | Organism |
---|---|
recombinant His-tagged IF2 from Escherichia coli by affinity chromatography and ion exchange chromatography | Escherichia coli |
Substrates | Comment Substrates | Organism | Products | Comment (Products) | Rev. | Reac. |
---|---|---|---|---|---|---|
GTP + H2O | - |
Escherichia coli | GDP + phosphate | - |
? | |
additional information | formation of the 70S-fMet-tRNAi Met-IF2-GDPNP complex. 70S ribosomes are isolated from Escherichia coli strain CAN20, recombinant His-tagged IF2 enzyme, non-hydrolyzable GTP analogue GDPNP | Escherichia coli | ? | - |
- |
Synonyms | Comment | Organism |
---|---|---|
IF-2 | - |
Escherichia coli |
IF2 | - |
Escherichia coli |
initiation factor 2 | - |
Escherichia coli |
ribosome-bound initiation factor 2 | - |
Escherichia coli |
translational guanosine triphosphatase | - |
Escherichia coli |
trGTPase | - |
Escherichia coli |
General Information | Comment | Organism |
---|---|---|
additional information | high-resolution structure for the key initiation trGTPase, initiation factor 2 (IF2), complexed with a nonhydrolyzable guanosine triphosphate analogue and initiator fMet-tRNAi Met in the context of the Escherichia coli ribosome to 3.7 A resolution using cryo-electron microscopy. Analysis of the intrinsic conformational modes of the 70S initiation complex (IC), establishing the mutual interplay of IF2 and initator transfer RNA (tRNA) with the ribsosome, mechanism of the final steps of translation initiation, overview. IF2-induced subunit joining of the 30S IC with the 50S subunit occurs in a rotated conformation and leads to the formation of the 70S-IC I. The initiator tRNA is positioned in the P/ei state through interactions with the L1 stalk and domain IV of IF2. Partial back rotation and unswiveling facilitate the P/pi state of initiator tRNA and reorient the G-domain of IF2 to trigger GTP hydrolysis. To reach the elongation-competent 70S complex, the 30S subunit completes back rotation, IF2-GDP dissociates, and the initiator tRNA completes the partial reverse translocation on the 50S subunit to reach the P/P-site state | Escherichia coli |