#working mrna

-- occurs right after transcription is initiated

-- seen in eukaryotes

-- happens on pre-mRNA

-- pre-mRNA still has introns

-- the 5′ end of pre-mRNA is modified

-- a 7-methylguanosine cap is added

-- this is also called a 5′ cap

-- initiated by adding GTP to the 5′ terminal nucleotide in reverse orientation, then adding methyl groups to the G residue

-- essential for production of working mRNA

-- 5′ cap aligns mRNA with ribosome

-- mRNA must align with ribosome in translation

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