I am trying to understand proteins at the molecular level, and I cant seem to understand one thing: how do you read the sequence of the proteins. For example, the enzyme Phosphofructokinase has the following amino acid sequence:

1 vrigliqgnr vlvvhdgfeg lakgqieeag wsyvggwtgq ggsklgtk

However, I cannot understand which amino acid the "a" stands for, or the "g", or the l" and "t" becasue more than one amino acid has the same starter letter. (e.g. Alanine, Arginine, Asparagine, and Aspartic acid all begin with the letter a)

How do you tell what each of the letter stands for