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| - | + | == Human Pre-initiation Complex (3j8c)== | |
| - | == | + | |
==Structure== | ==Structure== | ||
| + | |||
| + | Human Pre-initiation complex is an octameric molecule - it is composed of 8 polypeptide chain subunits. | ||
| + | |||
| + | The 43S initiation complex forms when Methionine initiation tRNA (Met-tRNAi(Met)) forms a ternary complex with Eukaryotic Initiation factor 2 (EIF2) and GTP. This complex then binds to the 40S subunit of the ribosome alongside EIF3, EIF1, and EIF1A. Finally, DHX29, a protein that aids structured mRNA scanning, binds to the 40S subunit as well. | ||
<StructureSection load='3j8c' size='340' side='right' caption='View of the full octamer complex''> | <StructureSection load='3j8c' size='340' side='right' caption='View of the full octamer complex''> | ||
==Function== | ==Function== | ||
| + | |||
| + | The completed 8-subunit complex binds to mRNA and "scans" from a 5' to 3' direction until it locates an initiation codon, at which point the Met-tRNAi(Met) binds to it. | ||
==Interactions== | ==Interactions== | ||
| + | |||
| + | The complex assembles around the 5' end of mRNA, and then proceeds to scan along the molecule in the 3' direction. | ||
| + | |||
| + | The assembly and operation of Human PIC occurs entirely in the cytosol. | ||
== Origin == | == Origin == | ||
| + | 3j8c originates in ''Homo sapiens'', but similar proteins are found in virtually all eukaryotes. | ||
== References == | == References == | ||
<references/> | <references/> | ||
Revision as of 20:58, 8 February 2017
Human Pre-initiation Complex (3j8c)
Structure
Human Pre-initiation complex is an octameric molecule - it is composed of 8 polypeptide chain subunits.
The 43S initiation complex forms when Methionine initiation tRNA (Met-tRNAi(Met)) forms a ternary complex with Eukaryotic Initiation factor 2 (EIF2) and GTP. This complex then binds to the 40S subunit of the ribosome alongside EIF3, EIF1, and EIF1A. Finally, DHX29, a protein that aids structured mRNA scanning, binds to the 40S subunit as well.
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