Forms an important part of the subunits of the ribosome. The _ are spliced back together to form the mRNA molecule. Is a nucleic acid that directs the production of proteins? Solution Protein forms an important part in the subunits of ribosomes. The precursor messenger RNA is spliced back together to form the mRNA molecule. Yes,nucleic acid (DNA or RNA) directs the production of proteins. They have informations for the process of gene expression..