1-Letter Amino Acid Abbreviations

Which letter represents valine in a protein sequence?

V

What is the one-letter code for tyrosine?

Y

How is tryptophan written in the one-letter code?

W

Which letter stands for threonine?

T

Serine is where enzymes often attach a phosphate group to switch a protein on or off. What is its one-letter code?

S

Proline and phenylalanine both start with P. Which letter is used for proline?

P

What letter stands for phenylalanine in a protein sequence?

F

Nearly every protein starts with methionine, because its codon AUG is the start codon. Write the one-letter code for methionine.

M

Lysine's one-letter code is not its first letter. Which letter is it?

K

What is the one-letter code for leucine?

L

Which letter is used for histidine?

H

Leucine and isoleucine are isomers with the same atoms. Which letter stands for isoleucine?

I

Glycine, glutamine and glutamic acid all start with G. Which letter does glycine use?

G

Which one-letter code is used for glutamic acid (glutamate)?

E

What is the one-letter code for glutamine?

Q

Write the one-letter code for cysteine.

C

Aspartic acid could not use its first letter. Which letter was it given?

D

Asparagine is the amide form of aspartic acid. What is its one-letter code?

N

In the one-letter code, which letter stands for arginine?

R

Alanine is one of the most common amino acids in proteins. What is its one-letter code?

A