Figure 4.

Isolation of an SLBP-displaying phage from a lung cDNA phage library. (A) In vitro selection from a human lung cDNA library was performed as in Fig. 3, except that the 3′-terminal stem loop of histone mRNA (120 nM) was used as the RNA bait. Sequence analysis confirmed that the cDNA insert in the amplified phage clone encoded SLBP. (B) Structure of the 3′ histone RNA stem loop used in this experiment. In addition, this RNA bore a 5′ leader and a 3′ tail annealed to a complementary biotinylated DNA oligonucleotide (the same as in Fig. 3C). (C) Schematic representation of full-length human SLBP (13, 14) and of the amino-terminally truncated form of SLBP (amino acid residues 87–270) displayed on the surface of the isolated phage clone. The region of SLBP comprising its minimal RNA-binding domain (residues 126–198) is shown in black (13).