Table 1. Properties of leucine zippers used in this study.

pI calculations were made using the site at http://us.expasy.org/tools/pi_tool.html. Leucine zippers for many of the baits and their in vitro interaction properties were described previously (13–15).

Combination	Bait	pI	Prey	Kd for bait-prey (in M)
1	EE12345L	4.2	EE12345L	Not detectable
2	RR12EE345L	6.5	RR12EE345L
3	EE34	5.3	EE34	8.1 × 10−4
4	RR34	10.5	RR34	3.9 × 10−5
5	RR1234 L	11.8	RR1234 L	2.5 × 10−7
6	RR34	10.5	EE34	1.0 × 10−8
7	EE34	5.3	RR34	1.0 × 10−8
8	RR12EE345L	6.5	EE12RR345L	1.3 × 10−11
9	EE12RR345L	10.4	RR12EE345L	1.3 × 10−11
10	RR12345L	12.2	EE12345L	1.1 × 10−11
11	RR1234 L	11.8	EE1234 L	1.0 × 10−15
12	EE1234 L	4.3	RR1234 L	1.0 × 10−15