A short basic domain supports a nucleic acid-binding activity in the rice tungro bacilliform virus open reading frame 2 product.

摘要

The full length rice tungro bacilliform badnavirus (RTBV) genome was cloned and used as a template for PCR amplification of open reading frame 2. Escherichia coli DH5alpha and BL21/DE3 (pLsS) strains were used as hosts for plasmid DNA preparation and protein expression, respectively. RTBV 2 product (P2) proteins had no sequence homologies, but possessed similar residues (basic, hydrophobic and proline) at their C-terminals. Mutations were introduced into the basic sequence (PPKKGIKRKYPA) and showedthat 4 of 5 basic residues, including a crucial lysine, were required for the binding of nucleic acids in a sequence-nonspecific manner. The sequence can also confer binding capacity when it is fused to the N-terminus of non-binding proteins.