Identification of the RNA binding regions of SRP68/72 and SRP72 by systematic mutagenesis of human SRP RNA.
RNA Biol
; 4(3): 154-9, 2007 Nov.
Article
em En
| MEDLINE
| ID: mdl-18347438
ABSTRACT
Within the large domain of the human signal recognition particle (SRP), 18 mutant SRP RNAs were constructed to disrupt Watson-Crick and G-U basepairs in helices 5, 6 and 8. Using a double-filter assay, the competitive binding of the mutant RNAs to purified human SRP68/72 or to a 7.4 kDa RNA-binding fragment of SRP72 (72frg) was measured. Binding of SRP68/72 was impaired by several mutations in the large domain with the most pronounced effects caused by changes in helix 5 (residues 222-231) and helix 8 (residues 176-191 and 202-214). Binding of the 72frg was diminished prominently by altering helix 5, in particular residues 120-128, and was unaffected by deleting helices 6 and 8. Deleting helix 8 diminished binding of SRP68/72 to a greater extent than deleting helix 6. The data suggest that nucleotide residues throughout most of the large SRP domain are directly and/or indirectly engaged in the binding of SRP68. In contrast, SRP72 binds only to a portion of the 5ef region.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
RNA
/
Mutagênese Sítio-Dirigida
/
Partícula de Reconhecimento de Sinal
/
Subunidades Proteicas
Tipo de estudo:
Diagnostic_studies
Limite:
Humans
Idioma:
En
Ano de publicação:
2007
Tipo de documento:
Article