Z-DNA-binding proteins. Identification critically depends on the proper choice of ligands.
J Biol Chem
; 265(31): 19112-5, 1990 Nov 05.
Article
en En
| MEDLINE
| ID: mdl-2172244
We have previously isolated from bull testis three proteins of molecular mass 31, 33, and 58 kDa that we have tentatively characterized as high affinity Z-DNA-binding proteins. This inference was based on their preferential binding to brominated poly(dG-dC).poly(dG-dC) in Z-form as opposed to the unbrominated polynucleotide in B-form (Gut, S. H., Bischoff, M., Hobi, R., and Kuenzle, C. C. (1987) Nucleic Acids Res. 15, 9691-9705). By partial amino acid sequencing we have provisionally identified the 31- and 33-kDa proteins as members of the high mobility group 2 and 1 protein families, respectively, whereas the 58-kDa protein has so far remained unidentified (Christen, Th., Bischoff, M., Hobi, R., and Kuenzle, C. C. (1990) FEBS Lett. 267, 139-141). In the present study, we have critically reassessed the binding specificity of these three proteins by using more natural Z- and B-DNA ligands. As such we chose supercoiled and relaxed DNA minicircles containing a d(CG)7 insert in the Z- and B-conformation, respectively. Filter binding tests and gel retardation assays performed with these ligands showed that the three testis proteins either do not discriminate between Z- and B-DNA (31- and 33-kDa proteins) or even have a preference for B-DNA (58-kDa protein). Therefore, we question the validity of using brominated poly(dG-dC).poly(dG-dC) as an indicator of Z-DNA binding.
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Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Testículo
/
ADN
/
Proteínas de Unión al ADN
Tipo de estudio:
Diagnostic_studies
/
Observational_studies
Límite:
Animals
Idioma:
En
Revista:
J Biol Chem
Año:
1990
Tipo del documento:
Article
País de afiliación:
Suiza
Pais de publicación:
Estados Unidos