Structural effects of LacI variants

 

TMD Change[1]

 

Variant

 

Assembly

Y282D Reversion[2]

Protein Stability

Chemical Modification

Solvent Exposure

Compared to WT

Monoclonal Exposure

UV Difference

Y7

 

W/Wless[3]

 

 

 

 

 

 

 

M42

 

I

 

X

 

 

 

 

 

L62

 

W/Wless[3]

 

 

 

 

 

 

 

I64

1

 

 

 

 

 

 

 

 

V66

1

 

 

 

 

 

 

 

 

L71

2

 

 

 

 

 

 

 

 

L73

3

 

 

 

 

 

 

 

 

H74

2

R
/Wless
[3]

 

X

 

 

 

 

 

S77

2

L[4]

 

 

 

 

ANS more apolar
KI: Less quenching/solvent exposure with IPTG change

 

Bigger >300 nm

Q78

1

 

 

 

 

 

 

 

 

V80

1

 

 

 

 

 

 

 

 

A81

 

V[5]

 

 

 

C107 IPTG sensitivity lost

 

 

Very small diff

I83

1

 

 

 

 

 

 

 

 

K84

1,2

E
R
A
L

 

  

 X[6]
X 

 

High[7]
Very high

 

 

WT6
WT
Decreased
Decreased

 

 All bigger[8] peaks

All bigger peaks

D88

1

 

 

 

 

 

 

 

 

L90

1

 

 

 

 

 

 

 

 

S93

1

 

 

 

 

 

 

 

 

V94

1

 

 

 

 

 

 

 

 

V95

 

 

 

 

 

 

 

 

 

V96

1

 

 

 

 

 

 

 

 

S97

1

 

 

 

 

 

 

 

 

M98

1

I

 

X

 

 

 

 

 

E100

1

W/Wless[3]

 

 

 

 

 

 

 

N113

1

 

 

 

 

 

 

 

 

Q117

1

W/Wless[3]

 

 

 

 

 

 

 

R118

 

 

 

 

 

 

 

 

 

Y126

1

 

 

 

 

 

 

 

 

L128

1

 

 

 

 

 

 

 

 

A133

 

T
V

 

X
X

 

 

 

 

 

L146

1

 

 

 

 

 

 

 

 

L148

 

F[9]

 

 

 

 

 

 

 

D149

1

N

 

X

 

 

 

 

 

V150

 

I

 

X

 

 

 

 

 

S151

 

P[8]

 

X

 

 

 

 

 

F161

3

 

 

 

 

 

 

 

 

S162

3

 

 

 

 

 

 

 

 

H163

3

 

 

 

 

 

 

 

 

E164

3

 

 

 

 

 

 

 

 

S191

 

F

 

X

 

 

 

 

 

S193

1

 

 

 

 

 

 

 

 

R197

1

G[10]
L
K

 

 

 

 

 

 

 

W201[11]

 

 

 

 

 

 

 

 

 

W22011

 

 

 

 

 

 

 

 

 

F226

 

W/Wless[3]

 

 

 

 

 

 

 

M223

 

I
T

 

X
X

 

 

 

 

 

M232

 

I

 

X

 

 

 

 

 

N246

3

S

 

X

 

 

 

 

 

Q248

3

R

 

X

 

 

 

 

 

L251

 

A[12]

 

 

 

 

 

 

 

Y273

 

W/Wless[3]

 

 

 

 

 

 

 

D274

3

N[13]
G
K[14]

 

X
X

   

Easily proteolyzed

 

 

   

More exposed

 

T276

2

A
I

 

X
X

 

 

 

 

 

D278

 

L[15]

 

 

 

 

 

 

 

C281[16]

 

S
A
F
M
I
S/282L

 

 

 

 

 

 

 

Y282[17]

 

D
F
A
L

Monomer

 

 

 

 

 

 

P284

 

S

 

X

 

 

 

 

 

K290

2

 

 

 

 

 

 

 

 

Q291

2

 

 

 

 

 

 

 

 

D292

2

 

 

 

 

 

 

 

 

F293

2

W/Wless[3]

 

 

 

 

 

 

 

L295

2

 

 

 

 

 

 

 

 

L296

2

M

 

X

 

 

 

 

 

V301

1

 

 

 

 

 

 

 

 

L304

1

 

 

 

 

 

 

 

 

L305

1

 

 

 

 

 

 

 

 

L318

3

 

 

 

 

 

 

 

 

L319

3

 

 

 

 

 

 

 

 

P320

3

A[8]

 

 

 

 

 

 

 

V321

3

I

 

X

 

 

 

 

 

S322

3

 

 

 

 

 

 

 

 

K325

 

W/Wless[3]

 

 

 

 

 

 

 

R326[18]

 

K
A
E
L
W

 

 

 

 

 

 

 

S354

 

F

 

X

 

 

 

 

 

References  

Bandyopadhyay, P. K. and C.-W. Wu (1979). "Heterogeneity of the Two Tryptophanyl Residues on the lac Repressor of Escherichia coli." Arch.Biochem.Biophys. 195, No. 2: 558-564.

Barry, J. K. and K. S. Matthews (1997). "Ligand-induced conformational changes in lactose repressor: a fluorescence study of single tryptophan mutants." Biochemistry 36(50): 15632-42.

Burns, L. E., A. H. Maki, et al. (1992). "Characterization of the two tryptophan residues of the lactose repressor from Escherichia coliby phosphorescence and optical detection of magnetic resonance." Biochemistry 32: 12821-12829.

Chakerian, A. E. and K. S. Matthews (1991). "Characterization of mutations in oligomerization domain of Lac repressor protein." J Biol Chem 266(33): 22206-14.

Chakerian, A. E., M. Pfahl, et al. (1985). "A mutant lactose repressor with altered inducer and operator binding parameters." J Mol Biol 183(1): 43-51.

Chang, W.-I., P. Barrera, et al. (1994). "Identification and characterization of aspartate residues that play key roles in the allosteric regulation of a transcription factor: Aspartate 274 is essential for inducer binding in lac repressor." Biochemistry 33: 3607-3616.

Chang, W. I. and K. S. Matthews (1995). "Role of Asp274 in lac repressor: Diminished sugar binding and altered conformational effects in mutants." Biochemistry 34(28): 9227-9234.

Chang, W. I., J. S. Olson, et al. (1993). "Lysine 84 is at the subunit interface of lac repressor protein." J Biol Chem 268(23): 17613-22.

Chen, J. and K. S. Matthews (1992). "T41 mutation in lac repressor is Tyr282----Asp." Gene 111(1): 145-6.

Chou, W. Y. and K. S. Matthews (1989). "Mutation in hinge region of lactose repressor protein alters physical and functional properties." J Biol Chem 264(11): 6171-6.

Daly, T. J. and K. S. Matthews (1986). "Characterization and modification of a monomeric mutant of the lactose repressor protein." Biochemistry 25(19): 5474-8.

Dong, F., S. Spott, et al. (1999). "Dimerisation mutants of Lac repressor. I. A monomeric mutant, L251A, that binds Lac operator DNA as a dimer." J Mol Biol 290(3): 653-66.

Flynn, T. C., L. Swint-Kruse, et al. (2003). "Allosteric transition pathways in the lactose repressor protein core domains: asymmetric motions in a homodimer." Protein Sci 12(11): 2523-41.

Gardner, J. A. and K. S. Matthews (1990). "Characterization of two mutant lactose repressor proteins containing single tryptophans." J Biol Chem 265(34): 21061-7.

Li, L. and K. S. Matthews (1995). "Characterization of Mutants Affecting the KRK Sequence in the Carboxyl-terminal Domain of lac Repressor." J.Biol.Chem. 270,no.18: 10640-10649.

Nichols, J. C. and K. S. Matthews (1997). "Combinatorial mutations of lac repressor. Stability of monomer-monomer interface is increased by apolar substitution at position 84." J Biol Chem 272(30): 18550-7.

Ozarowski, A., J. K. Barry, et al. (1999). "Ligand-induced conformational changes in lactose repressor: a phosphorescence and ODMR study of single-tryptophan mutants." Biochemistry 38(21): 6715-22.

Royer, C. A., J. A. Gardner, et al. (1990). "Resolution of the fluorescence decay of the two tryptophan residues of lac  repressor using single tryptophan mutants." Biophys J 58: 363-378.

Schmitz, A., U. Schmeissner, et al. (1976). "Mutations affecting the quaternary structure of the lac repressor." J Biol Chem 251(11): 3359-66.

Spott, S., F. Dong, et al. (2000). "Dimerisation mutants of Lac repressor. II. A single amino acid substitution, D278L, changes the specificity of dimerisation." J Mol Biol 296(2): 673-84.

Spotts, R. O., A. E. Chakerian, et al. (1991). "Arginine 197 of lac repressor contributes significant energy to inducer binding. Confirmation of homology to periplasmic sugar binding proteins." J Biol Chem 266(34): 22998-3002.

Swint-Kruse, L., C. R. Elam, et al. (2001). "Plasticity of quaternary structure: twenty-two ways to form a LacI dimer." Protein Sci 10(2): 262-76.

Swint-Kruse, L., H. Zhan, et al. (2003). "Perturbation from a distance: mutations that alter LacI function through long-range effects." Biochemistry 42(47): 14004-16.

Swint-Kruse, L., H. Zhan, et al. (2005). "Integrated insights from simulation, experiment, and mutational analysis yield new details of LacI function." Biochemistry 44(33): 11201-13.  


Footnotes

[1]
Number indicates whether residue participates in pathways 1, 2, or 3.   (Flynn, Swint-Kruse et al. 2003)

[2] (Swint-Kruse, Elam et al. 2001)

[3] (Barry and Matthews 1997)

[4] All data:  (Chou and Matthews 1989)

[5] All data:  (Chakerian, Pfahl et al. 1985)

[6] A, E, R, L : (Chang, Olson et al. 1993)

[7] A, L:  (Nichols and Matthews 1997)

[8] A, L:  (Swint-Kruse, Zhan et al. 2005)

[9] (Swint-Kruse, Zhan et al. 2003)

[10] (Spotts, Chakerian et al. 1991)

[11] (Bandyopadhyay and Wu 1979; Gardner and Matthews 1990; Royer, Gardner et al. 1990; Burns, Maki et al. 1992; Barry and Matthews 1997; Ozarowski, Barry et al. 1999)

[12] (Dong, Spott et al. 1999)

[13] (Chang and Matthews 1995)

[14] (Chang, Barrera et al. 1994)

[15] LOTS OF OTHER MUTATIONS IN THIS PAPER (Spott, Dong et al. 2000)

[16] (Chakerian and Matthews 1991)

[17] (Schmitz, Schmeissner et al. 1976; Daly and Matthews 1986; Chakerian and Matthews 1991; Chen and Matthews 1992)

[18] (Li and Matthews 1995)