/usr/share/genometools/gtdata/trans/TransProt20 is in genometools-common 1.5.1-2ubuntu1.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 | # 20-character amino acid alphabet in upper case
L
V
I
F
K
R
E
D
A
G
S
T
N
Q
Y
W
P
H
M
C
XUBZJO*-
|