Table 2 Activity of mutants and conservation of functionally important residues

From: Structural insights into the committed step of bacterial phospholipid biosynthesis

Construct

Activitya, %

G3P K m (mM), (number-fold increase)b

k cat (s−1)

k cat / K m (s−1 mM−1), (number-fold decrease)c

Conservation, %

WT

100

1.39, (1.0)

13.4

9.6, (1.0)

 

S35A

4.76

13.75, (9.9)

0.64

0.05, (205.8)

92.5, D (2.7)d, T (0.9)

S35C

4.35

20.47, (14.7)

0.59

0.03, (334.9)

 

S35T

17.25

5.01, (3.6)

2.33

0.47, (20.7)

 

N37A

18.38

3.04, (2.2)

2.49

0.82, (11.8)

88.3, S (6.0), G (2.0)

N37D

0.88

13.72, (9.8)

0.12

0.01, (1,109.5)

 

N37H

10.10

10.07, (7.2)

1.37

0.14, (71.0)

 

N37Q

9.48

14.24, (10.2)

1.28

0.09, (107.0)

 

N37S

18.31

1.25, (0.9)

2.48

1.99, (4.9)

 

T41A

4.75

0.43, (0.3)

0.64

1.49, (6.5)

86.4, S (3.1), R (3.0)

T41S

44.86

1.98, (1.4)

6.07

3.07, (3.1)

 

R45A

1.13

50.46, (36.2)

0.15

0.003, (3,189.8)

92.2, A (1.4), K (1.0)

R45K

6.25

19.32, (13.9)

0.85

0.04, (220.2)

 

H92A

17.48

2.64, (1.9)

2.37

0.9, (10.8)

97.8, N (0.5), Q (0.1)

H92D

2.42

6.31, (4.5)

0.33

0.05, (185.7)

 

H92E

NA e

    

H92K

2.02

44.61, (32.0)

0.27

0.01, (1,576.5)

 

H92L

13.91

5.43, (3.9)

1.88

0.35, (27.8)

 

H92N

6.91

1.26, (0.9)

0.93

0.74, (13.0)

 

H92Q

16.15

5.56, (4.0)

2.19

0.39, (24.5)

 

G102A

13.74

9.97, (7.2); 7-fold increasef

1.86

0.19, (51.7)

97.9, S (0.5), R (0.1)

G103A

13.97

6.74, (4.8); 7-fold increasef

1.89

0.28, (34.3)

 

K104A

7.42

6.58, (4.7)

1.00

0.15, (63.2)

94.8, R (2.6), G (0.5)

K104R

25.47

2.00, (1.4)

3.45

1.72, (5.6)

 

G105A

30.20

3.58, (2.6)

4.09

1.14, (8.5)

73.2, A (21.3), S (3.4)

G105P

0.09

2.08, (1.5)

0.01

0.01, (1,698.9)

 

V106G

4.35

0.98, (0.7)

0.59

0.60, (16.1)

79.2, I (13.6), A (2.0)

V106P

1.56

21.84, (15.7)

0.21

0.01, (995.1)

 

A107P

13.32

21.74, (15.6)

1.80

0.08, (116.3)

88.1, S (6.2), L (1.7)

S142A

31.69

2.89, (2.1)

4.29

1.48, (6.5)

52.6, A (33.0), G (5.2)

H177A

6.52

9.24, (6.6)

0.88

0.10, (100.9)

91.4, N (2.2), F (1.0)

H177D

0.25

82.13, (59.0)

0.03

0.0004, (23,028.0)

 

H177E

1.08

41.08, (29.5)

0.15

0.004, (2,709.5)

 

H177F

0.32

33.27, (23.9)

0.04

0.0013, (7,493.0)

 

H177I

0.79

15.34, (11.0)

0.11

0.01, (1,381.2)

 

H177K

3.74

13.63, (9.8)

0.51

0.04, (259.6)

 

H177L

2.54

3.78, (2.7)

0.34

0.09, (105.9)

 

H177M

5.14

3.20, (2.3)

0.70

0.22, (44.3)

 

H177N

1.74

10.50, (7.5)

0.24

0.02, (429.4)

 

H177Q

1.00

3.08, (2.2)

0.14

0.04, (218.9)

 

H177Y

0.03

0.94, (0.7)

0.004

0.005, (2,055.5)

 

N180A

4.59

26.31, (18.9)

0.62

0.02, (408.7)

89.1, D (1.7), G (0.5)

N180D

3.31

30.37, (21.8)

0.45

0.01, (652.7)

 

N180H

0.95

19.95, (14.3)

0.13

0.01, (1,490.5)

 

N180Q

2.26

23.37, (16.8)

0.31

0.01, (737.3)

 

R183A

43.17

3.84, (2.8)

5.84

1.52, (6.3)

73.4, K (7.1), N (5.3)

R183E

43.94

10.33, (7.4)

5.95

0.58, (16.7)

 

R183K

40.77

2.37, (1.7)

5.52

2.33, (4.1)

 

E189A

136.94

5.79, (4.2)

18.53

3.20, (3.0)

88.0, G (1.1), K (0.5)

E189D

39.03

2.81, (2.0)

5.28

1.88, (5.1)

 

E189Q

12.01

15.10, (10.8)

1.63

0.11, (89.6)

 
  1. aActivities are shown as percentages to that of the wild-type (34.55 μmol min−1 mg−1). See Fig. 4e for activity measurement of mutants
  2. bIncreased folds compared with the G3P K m of the wild-type aaPlsY
  3. cDecreased folds compared with the specificity constant of the wild-type
  4. dNumbers in brackets indicate frequency of the alternative residues found in 7,288 unique sequences of homologs from a BLAST69 search against the InterPro 60.0 database70
  5. ePurification of this mutant was unsuccessful. fData taken from literature12
Back to article page