DNA-Binding Activity of the C2 Protein of Tomato Yellow Leaf Curl Geminivirus

• Published in: Virology (New York, N.Y.) N.Y.), 1996-03, Vol.217 (2), p.607-612
• Main Authors: NORIS, E., JUPIN, I., ACCOTTO, G.P., GRONENBORN, B.
• Format: Article
• Language: English
• Subjects: Base Sequence; Binding Sites; DNA Primers - chemistry; DNA-Binding Proteins - metabolism; Geminiviridae - genetics; Lycopersicon esculentum; Molecular Sequence Data; tomato leaf curl virus; Viral Proteins - metabolism
• ISSN: 0042-6822; 1096-0341
• DOI: 10.1006/viro.1996.0157

Thein vitroDNA-binding activity of the C2 protein of tomato yellow leaf curl geminivirus (TYLCV) was studied following its expression inEscherichia colias a fusion protein with an His tag N-terminal extension (His-C2). Southwestern blotting experiments demonstrated that the C2 protein is able to bind both single-stranded and double-stranded DNA probes. In electrophoretic mobility shift assays performed using purified protein and single-stranded DNA probes several shifted complexes were formed. The presence of NaCl (up to 800 mM) did not substantially affect binding profiles, demonstrating a stable interaction. His-C2 appeared to bind single-stranded DNA in a sequence-nonspecific manner, with a preference for single-stranded compared to double-stranded DNA. Deletion mutants demonstrated that the central core of C2 (amino acids 33 to 104), which contains a Cys-His rich region, is sufficient for conferring binding activity. The potential significance of this DNA-binding activity with respect to possible biological functions of TYLCV C2 protein is discussed.