Binding site of the M-domain of human protein SRP54 determined by systematic site-directed mutagenesis of signal recognition particle RNA

Krishne Gowda, Kimberly Chittenden, Christian Zwieb

Research output: Contribution to journalArticle

27 Scopus citations

Abstract

The interaction of protein SRP54M from the human signal recognition particle with SRP RNA was studied by systematic site-directed mutagenesis of the RNA molecule. Protein binding sites were identified by the analysis of mutations that removed individual SRP RNA helices or disrupted helical sections in the large SRP domain. The strongest effects on the binding activity of a purified polypeptide that corresponds to the methionine-rich domain of SRP54 (SRP54M) were caused by changes in helix 8 of the SRP RNA. Binding of protein SRP19 was diminished significantly by mutations in helix 6 and was stringently required for SRP54M to associate. Unexpectedly, mutant RNA molecules that resembled bacterial SRP RNAs were incapable of interaction with SRP54M, showing that protein SRP19 has an essential and direct role in the formation of the ternary complex with SRP54 and SRP RNA. Our findings provide an example for how, in eukaryotes, an RNA function has become protein dependent.

Original languageEnglish (US)
Pages (from-to)388-394
Number of pages7
JournalNucleic acids research
Volume25
Issue number2
DOIs
StatePublished - 1997

ASJC Scopus subject areas

  • Genetics

Fingerprint Dive into the research topics of 'Binding site of the M-domain of human protein SRP54 determined by systematic site-directed mutagenesis of signal recognition particle RNA'. Together they form a unique fingerprint.

  • Cite this