# Amino acid 1-letter code 3-letter code atoms MW codons alanine A Ala 5 89 GCU GCC GCA GCG arginine R Arg 11 174 CGU CGC CGA CGG AGA AGG asparagine N Asn 8 132 AAU AAC aspartic acid D Asp 8 133 GAU GAC cysteine C Cys 6 121 UGU UGC glutamic acid E Glu 9 146 GAA GAG glutamine Q Gln 9 147 CAA CAG glycine G Gly 4 75 GGU GGC GGA GGG histidine H His 10 155 CAU CAC isoleucine I Ile 8 131 AUU AUC AUA leucine L Leu 8 131 UUA UUG CUU CUC CUA CUG lysine K Lys 9 146 AAA AAG methionine M Met 8 149 AUG phenylalanine F Phe 11 165 UUU UUC proline P Pro 7 115 CCU CCC CCA CCG serine S Ser 6 105 UCU UCC UCA UCG AGU AGC threonine T Thr 7 119 ACU ACC ACA ACG tryptophan W Trp 13 204 UGG tyrosine Y Tyr 11 181 UAU UAC valine V Val 7 117 GUU GUC GUA GUG