-10

0

10

20

30

40

50

60

c-Srcwt

K442A D518A

0

50

100

150

200

250

300

350

400

Csk wt R279A R281A R283A R384A R389A

Helix I

Arg 389

Arg 384

Glu 517

Asp 518

Figure 3 A

180°

Helix I'90°

D

Helix D

Arg 283 Glu 510

Lys 442Arg 281

Glu 504αH/αI loop

Helix I

E

Binding of Csk to interface mutants of c-SrcBinding of interface mutants of Csk to c-Src

B Cc-Src Csk

Res

po

nse

Un

its

Res

po

nse

Un

its

Arg 279

Tyr 511

Helix D

Helix I

αH/αI loop

Helix DHelix C

Helix I

0

0.2

0.4

0.6

0.8

1

1.2

wt K442A E510A D518A

Src construct

Phosphorylation of mutants of c-Src by Csk

Rel

ativ

e Ph

osp

ho

ryla

tio

n