TABLE 1.

Expression and binding of RAG1 core variants

	R1 variantsa	Protein yieldb	RAG2 bindingc
1	384–1008	++	++
2	528–777	+	−
3	528–1008	++	−
4	761–980	+++	−
5	761–1008	−	NDd
6	Δ721–760	+++	++
7	Δ464–512	+	−
8	499–508Ae	−	ND
9	477–493Ae	−	ND
10	Δ512–528	−	ND
11	384–555∼983–1008	−	ND
12	464–555∼983–1008	−	ND
13	384–518∼960–1008	+	−
14	383–732∼960–1008	++	++
15	384–585∼960–1008	−	ND
16	464–732∼960–1008	++++	++
17	384–732	+	−
18	528–732∼960–1008	+++	−
19	479–732∼960–1008	++++	++
20	508–732∼960–1008	+++	+
21	508–732∼960–997	+++	−

^a All variants were N-terminal MBP- and C-terminal His₆-tagged.

^b Protein yield and quality were evaluated by FPLC. ++, expression typical for MBP-R1c; ++++, expression typical for MBP-Mini-RAG1, which is ∼5-fold greater than that of MBP-R1c; +, expression reduced at least 2-fold from MBP-R1c.

^c Ability to bind to GST-RAG2 core was tested by BLItz and GST pulldown. ++, binding as seen between R2c and either R1c or Mini-RAG1; +, binding reduced 3–20 fold; −, little or no binding detected.

^d ND means not done.

^e The indicated residues were substituted by alanine.