Aminoacyl-tRNA synthetase bound to its cognate tRNA

Here we see tRNA^Gln bound to glutaminyl-tRNA synthetase (specific for it)
(This model contains only the backbone of both chains, that is, the phosphous atoms of RNA and the alpha carbon atoms of protein; you can see this by changing the rendering to Style > Scheme > Spacefill).

Note how the synthetase contacts mainly with the 3' end of tRNA (where it binds the amino acid) and with the anticodon loop. This allows the enzyme to recognise just a single amino acid and a single tRNA, so setting the amino acid-anticodon specificity. For this reason, the aminoacyl-tRNA synthetases are said to be "the second genetic code".

In this case, tRNA^Asp bound to its cognate aspartyl-tRNA synthetase.
(This model does include all atoms, so it is slower)

Colour by secondary structure:

Alpha helices
Beta sheets
Without a regular secondary structure

Spacefilling model.