TABLE 6.

Stoichiometry of PTB1 constructs bound to HCV 3′-NTR RNA constructs

	RNA
Protein	3′-NTR	X RNA	SLI	SLII/SLIII	SLIII
PTB1	6 ± 1	2	0	0	1
PTB1:12	8 ± 1	2	0	0	1
PTB1:23	2a	0
PTB1:34	15 ± 1	0	0	0	0

Binding of PTB1 protein constructs to the 3′-NTR of HCV and X constructs. Binding in 100 mM NaCl, 1 mM MgCl₂, 10 mM sodium cacodylate (pH 7), 20 μg/mL BSA, 10 μg/mL tRNA.

^aThis result is anomalous. EMSA experiments showed that most of the RNA was found in the well of the lanes at PTB1:23 concentrations >22 nM. This complex appears to have a tangled superstructure with an unknown stoichiometry.