ed**A total of four amino acids differ between the monkey and human sequences. ** The sequences of the monkey and human proteins are almost identical, with only a few differences in amino acid sequences. The difference between the two species lies in the substitution of four specific amino acids in some regions of the protein.
Specifically, the human protein has a substitution of histidine instead of isoleucine at position 133, and tryptophan instead of arginine at position 14 Furthermore, the human protein has a substitution of serine at position 76, and a substitution of glutamic acid at position 98, which are not present in the monkey sequence.
These four amino acids have been shown to give the human protein a different conformation and likely a different function compared to the monkey sequence.