What are the subunits of protein?
The subunits of proteins are called amino acids.
I will not stop saying that cryo-EM links what is known about energy-dependent changes in the microRNA/messenger RNA balance from electrons to ecosystems via fixation of amino acid substitutions in the context of the pheromone-controlled physiology of reproduction, which has been linked to all biophysically constrained viral latency and all biodiversity.
And, obviously, serious scientists are not going to stop confirming that fact.
See: Noguchi Y et al, “Cryo-EM structure of Mcm2-7 double hexamer on DNA suggests a lagging-strand DNA extrusion model” appears in Proceedings of the National Academy of Sciences the week of October 23, 2017.
See also:
RNA-mediated molecular epigenetics and virus-driven entropy
RNA mediated molecular epigenetics and virus driven entropy (video)