Which of the following are characteristics of MHC Class I molecules?
1) β2 microglobulin is larger than the alpha chain
2) The alpha chain and β2 microglobulin have the same size
3) The peptide/binding site is on the alpha chain
4) The alpha chain and β2 microglobulin are encoded in the same gene complex
5) E) The alpha chain consists of two homodimers