Dimerization and DNA-binding of ASR1, a small hydrophilic protein abundant in plant tissues suffering from water loss

LAURA MASKIN*, NICOLÁS FRANKEL*; GUSTAVO GUDESBLAT; MARÍA, J. DEMERGASSO; LÍA I. PIETRASANTA; NORBERTO D. IUSEM; * IGUAL CONTRIBUCIÓN

BIOCHEMICAL AND BIOPHYSICAL RESEARCH COMMUNICATIONS

ACADEMIC PRESS INC ELSEVIER SCIENCE

Año: 2007 vol. 352 p. 831 - 835

0006-291X

The Asr gene family is present in Spermatophyta. Its members are generally activated under water stress. We present evidence thattomato ASR1, one of the proteins of the family, accumulates in seed during late stages of embryogenesis, a physiological process characterizedby water loss. In vitro, electrophoretic assays show a homo-dimeric structure for ASR1 and highlight strong non-covalent interactionsbetween monomers prone to self-assemble. Direct visualization of single molecules by atomic force microscopy (AFM) confirmsthat ASR1 forms homodimers and that uncovers both monomers and dimers bind double stranded DNA.