Type I V loops and type II V arms

tRNA evolution

The type II tRNA V arm (initially 14 nucleotides) was formed from ligation of a 3’-acceptor stem (7 nucleotides; CCGCCGC) to a 5’-acceptor stem (7 nucleotides; GCGGCGG).

The type I tRNA V loop (initially CCGCC) was processed from the 14 nucleotide type II V arm (initially CCGCCGCGCGGCGG) by an internal 9 nucleotide deletion (removing GCGCGGCGG).

The news reported here is from ~4.2 billion years ago.

Think of tRNA as a living molecular fossil from ~4.2 billion years ago. This is much older than a T-rex skeleton (~75 million years ago).

The press has missed a story, here.

Chemical Evolution of Life on Earth

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