<s>
In	O
biochemistry	O
,	O
a	O
Ramachandran	B-Application
plot	I-Application
(	O
also	O
known	O
as	O
a	O
Rama	B-Application
plot	I-Application
,	O
a	O
Ramachandran	B-Application
diagram	I-Application
or	O
a	O
 [ φ , ψ ] 	O
plot	O
)	O
,	O
originally	O
developed	O
in	O
1963	O
by	O
G	O
.	O
N	O
.	O
Ramachandran	O
,	O
C	O
.	O
Ramakrishnan	O
,	O
and	O
V	O
.	O
Sasisekharan	O
,	O
is	O
a	O
way	O
to	O
visualize	O
energetically	O
allowed	O
regions	O
for	O
backbone	O
dihedral	O
angles	O
ψ	O
against	O
φ	O
of	O
amino	O
acid	O
residues	O
in	O
protein	O
structure	O
.	O
</s>
<s>
Because	O
dihedral	O
angle	O
values	O
are	O
circular	O
and	O
0°	O
is	O
the	O
same	O
as	O
360°	O
,	O
the	O
edges	O
of	O
the	O
Ramachandran	B-Application
plot	I-Application
"	O
wrap	O
"	O
right-to-left	O
and	O
bottom-to-top	O
.	O
</s>
<s>
A	O
Ramachandran	B-Application
plot	I-Application
can	O
be	O
used	O
in	O
two	O
somewhat	O
different	O
ways	O
.	O
</s>
<s>
One	O
might	O
expect	O
that	O
larger	O
side	O
chains	O
would	O
result	O
in	O
more	O
restrictions	O
and	O
consequently	O
a	O
smaller	O
allowable	O
region	O
in	O
the	O
Ramachandran	B-Application
plot	I-Application
,	O
but	O
the	O
effect	O
of	O
side	O
chains	O
is	O
small	O
.	O
</s>
<s>
Hence	O
it	O
is	O
least	O
restricted	O
,	O
and	O
this	O
is	O
apparent	O
in	O
the	O
Ramachandran	B-Application
plot	I-Application
for	O
glycine	O
(	O
see	O
Gly	O
plot	O
in	O
gallery	O
)	O
for	O
which	O
the	O
allowable	O
area	O
is	O
considerably	O
larger	O
.	O
</s>
<s>
In	O
contrast	O
,	O
the	O
Ramachandran	B-Application
plot	I-Application
for	O
proline	O
,	O
with	O
its	O
5-membered-ring	O
side	O
chain	O
connecting	O
Cα	O
to	O
backbone	O
N	O
,	O
shows	O
a	O
limited	O
number	O
of	O
possible	O
combinations	O
of	O
ψ	O
and	O
φ	O
(	O
see	O
Pro	O
plot	O
in	O
gallery	O
)	O
.	O
</s>
<s>
The	O
first	O
Ramachandran	B-Application
plot	I-Application
was	O
calculated	O
just	O
after	O
the	O
first	O
protein	O
structure	O
at	O
atomic	O
resolution	O
was	O
determined	O
(	O
myoglobin	O
,	O
in	O
1960	O
)	O
,	O
although	O
the	O
conclusions	O
were	O
based	O
on	O
small-molecule	O
crystallography	O
of	O
short	O
peptides	O
.	O
</s>
<s>
While	O
the	O
Ramachandran	B-Application
plot	I-Application
has	O
been	O
a	O
textbook	O
resource	O
for	O
explaining	O
the	O
structural	O
behavior	O
of	O
peptide	O
bond	O
,	O
an	O
exhaustive	O
exploration	O
of	O
how	O
a	O
peptide	O
behaves	O
in	O
every	O
region	O
of	O
the	O
Ramachandran	B-Application
plot	I-Application
was	O
only	O
recently	O
published	O
(	O
Mannige	O
2017	O
)	O
.	O
</s>
<s>
The	O
Molecular	O
Biophysics	O
Unit	O
at	O
Indian	O
Institute	O
of	O
Science	O
celebrated	O
50	O
years	O
of	O
Ramachandran	B-Application
Map	I-Application
by	O
organizing	O
International	O
Conference	O
on	O
Biomolecular	O
Forms	O
and	O
Functions	O
from	O
8	O
–	O
11	O
January	O
2013	O
.	O
</s>
<s>
UCSF	B-Application
Chimera	I-Application
,	O
found	O
under	O
the	O
Model	O
Panel	O
.	O
</s>
