Known functional effects of mutating hypothesized charged residues. 

Values are straight multiplications of WT affinities, so that 25 x WT is weaker binding and ½ WT is tighter binding.

 

 
Phenotype[1]

 
Variant

 
O1 DNA

 
DNA + IPTG

IPTG pH 7.4

IPTG pH 9.2

IPTG +DNA

IPTG kinetics

 
Allostery

DNA Release

WT

 

 

~10-11 M

~ 10-7M or
10,000 x DNA

~10-6 M

~10-5 M or
10 x pH 7.4

~10-5 M  or 10 x pH 7.4

 

 

 

Y7

 

W/Wless[2]

 

 

 

 

 

 

 

 

V52

 

A[3]  C-red[4]
C-ox
D
E
F
G
H
L
P
Q
R
S
T
W

 

 

 

 

 

 

 

 

Q55

 

E[5]

Very low

 

 

 

 

 

 

 

G58

 

+G[6]

 

 

 

 

 

 

 

 

Q60

 

G6
P
G+G
G+2G
G+3G

 

 

 

 

 

 

 

 

L62

 

W/Wless[2]

 

 

 

 

 

 

 

 

H74

Some s

 
A[7]
L
D
F
W
W/Wless[2]
D/H278[8]

 
25 x WT
10 x WT
2 x WT
~1/3 WT
~1/3WT 

2 x WT

 
¾ WT
5/8 WT
WT
½ x WT
12 x DNA 

¼ x WT

 
~WT
~WT
~WT
10 x WT

 
~WT

 
= pH 7.4
= pH 7.4
= pH 7.4
7 x pH 7.4

 = pH 7.4

 
2 x pH 7.4
2 x pH 7.4
4 x pH 7.4
14 x pH 7.4
 
2 x pH 7.4

 

 
IPTG bias
IPTG bias 

DNA bias

 
IPTG bias

 

S77

Weak –
P is ws

L[9]

nonspecific

 

Biphasic
WT/10-5

~ pH 7.4

 

 

 

 

A81

- or s

V[10]

nonspecific

WT (nonspecific)

½ WT

 

 

Slower

 

 

K84

Mostly s 

R is +
E is ws

 R[11]
E
A

L

WT
WT
WT 

4 x WT

  

7 x DNA[12]
5 x DNA 

10 x WT
WT
WT 

WT

2 x pH 7.4
= pH 7.4~ pH 7.4 

2 x pH 7.4

 

 

Slow/
Biphasic
Slow/
biphasic

 

 Reduced[12]

 Reduced

 

WT and 2ndIPTG[12]
WT and  2ndIPTG

D88

All s

 A[13]
E
K
N

 

 

 

 

 

 

 

 

E100[14]

+

L 

W/Wless[2]

WT

 

~WT or
tighter

= pH 7.4
↑ coop'tvty

Tighter than WT

 

Reduced?

 

A110

 

 T[15]
K

weaker?
weaker?

 

~WT
100 x WT

 

 

 

 

 

Q117

 

W/Wless[2]

 

 

 

 

 

 

 

 

R118

Weak -,
K and E are
-

 

 

 

 

 

 

 

 

 

D130

 

 A[13]
E
K
N