Full-length SRY protein is essential for DNA binding.
SRY directs testicular development. It has been suggested that the only high-mobility group (HMG) box of the SRY is important for the function of this protein; however, other studies have suggested that the N- and C-terminal regions are also involved in this process. Herein, we analysed and compared in vitro the DNA-binding activity of the full-length SRY and three mutants (HMG box alone, N-terminal less and C-terminal less SRY proteins). DNA-binding capability was analysed by mobility shift assays, optical density and dissociation constant by using pure non-fusion SRY proteins. The structure of the full-length SRY was carried out using a protein molecular model. The HMG box SRY alone and C-terminal less SRY proteins had a statistically diminished DNA binding in comparison with the full-length SRY. In contrast, the affinity for DNA of the N-terminal less SRY was relatively similar to the full-length SRY. Likewise, three-dimensional structure of the full-length SRY suggested that some residues of the C-terminal region of the SRY interact with DNA. We demonstrate the importance that full-length SRY has, particularly the C-terminal region of the protein, in DNA binding in vitro. Likewise, the affinity of the HMG box alone is clearly reduced when compared with the full-length SRY.
Sánchez-Moreno
I
I
Unidad de Investigación Médica en Biología del Desarrollo, Centro Médico Nacional Siglo XXI, Coordinación de Investigación en Salud, Instituto Mexicano del Seguro Social, C.P. 06720 México, D.F., Mexico.
Coral-Vázquez
R
R
Méndez
J P
JP
Canto
P
P
D004247:DNA / Q000378:metabolism*; D004268:DNA-Binding Proteins / Q000737:chemistry / Q000378:metabolism / Q000502:physiology; D005982:Glutathione Transferase / Q000737:chemistry / Q000378:metabolism; D024742:HMG-Box Domains / Q000502:physiology; D006801:Humans; D066298:In Vitro Techniques; D008958:Models, Molecular; D017434:Protein Structure, Tertiary / Q000502:physiology; D011993:Recombinant Fusion Proteins / Q000737:chemistry / Q000378:metabolism; D051876:Sex-Determining Region Y Protein / Q000737:chemistry / Q000378:metabolism* / Q000502:physiology*
D004268:DNA-Binding Proteins; D011993:Recombinant Fusion Proteins; C497745:SRY protein, human; D051876:Sex-Determining Region Y Protein; D004247:DNA; D005982:Glutathione Transferase