TABLE 1.

N-terminal deletion and point mutant proteins of BirA plus OmpR protein mutants

Repression	Biotin requirementa	Mutation siteb	Secondary structurec	OmpR mutantd	Reference
	nm
+	1.6	None			Ref. 16
++	1.6	T52S	Wing		This study
+	1.6	T52I	Wing	T224I	This study
+	1.6	V53A	Wing		This study
+	1.6	V53M	Wing		This study
+	1.6	G55S	Wing		This study
−	1.6	G57S	Wing	G229S	This study
−	1.6	Y58F	Wing		This study
+	1.6	Y58T	Wing		This study
−	41–4000	Δ2–65	wHTH		Ref. 11
−	41–4000	Δ2–63	wHTH		Ref. 12
−	41–4000	Δ3–60	wHTH		This study
−	41–4000	Δ3–40	Helix I, II, III		This study
−	41–4000	Δ3–25	Helix I, II		This study
−	41–4000	Δ48–61	ΔWing		This study
−	1.6	50–62 substitution	Chimera		This study
−	4000	G115S	BBLe		Refs. 15 and 19
−	41–4000	R118G	BBL		Ref. 16
−	4	R119W	BBL		Ref. 16

^a The minimal biotin requirements of the deletion and the point mutants constructed in this study. The data for the N-terminal mutants are directly from Refs. 15, 16, and 19.

^b Positions are amino acid residue positions.

^c Locations of the mutations in the secondary structure of BirA protein.

^d Wing residue substitutions having regulatory effects in the OmpR system.

^e BBL, biotin binding loop.