= Bacterial initiation factor IF2
\b[Bacterial initiation factor IF2] is a <GTPase> and <bacterial translation initiation factor> that helps recruit and position the <initiator transfer RNA> in bacterial <biological translation>. Its C-terminal region recognizes the attached <formylmethionine>. <GTP> binding and <GTP hydrolysis> participate in the transition toward a complete elongation-competent <ribosome>.<Large-Scale Movements of IF3 and tRNA during Bacterial Translation Initiation by Tanweer Hussain and others>[Introduction and Results, IF2 and initiator-tRNA positioning]{ref}
The relevant objects are distinct: <bacterial initiation factor IF2> is a <protein>, <GTP> is a bound <nucleotide>, and <formylmethionine> is carried by <transfer RNA>. Recognizing the attached <amino acid> is not the same reaction as charging the <transfer RNA>.
In an original assay design, compare initiator-tRNA binding to a <30S initiation complex> with a later measurement of <peptide bond> formation after adding the <large ribosomal subunit>. A preparation could bind the carrier successfully yet fail at a subsequent rearrangement. The two readouts therefore test different stages, rather than two interchangeable measures of IF2 activity.
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