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Predicate | Object |
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rdf:type | |
lifeskim:mentions | |
pubmed:issue |
3
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pubmed:dateCreated |
1997-7-1
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pubmed:abstractText |
Protein SRP19 is a 144-amino-acid polypeptide that associates intimately with the signal-recognition particle RNA (SRP RNA) and serves as an important structural and functional component of the SRP. We investigated the structure and RNA-binding activity of the human SRP19 protein by the use of comparative sequence analysis, high-stringency structure prediction, proteolytic susceptibility, and site-directed mutagenesis. SRP19 was found to consist of two distinct regions (called N-terminal and C-terminal regions) that are separated by a boundary of approximately 12-15 amino acid residues. Both regions contain an alpha-helix and several beta-strands that are connected by loops or turns. In agreement with the hypothetical model, proteolytic susceptibility demonstrated the predominant accessibility of two sites: one in a surface loop of the N-terminal region (YLNNKKTIAEGR33), and another site in the C-terminal tail at residues L129 and E133. The RNA-binding activities of mutant polypeptides with changes of conserved lysines and arginines (mutants K27Q, R33Q and R34Q) demonstrated that the proteolytically accessible loop of the N-terminal region is in direct contact with the SRP RNA. In contrast, alteration of a certain basic amino acid residues in the C-terminal region (R83, K116 and R118), as well as a deletion of four amino acid residues located at the boundary between the two regions, had no effect on the RNA-binding ability. The structural model that emerges from our data is thematically similar to that of ribosomal protein S5, the N-domain of which contains a loop motif believed to interact with double-stranded RNA. The presence of a similar structural feature in protein SRP19 has significant implications for the structure and function of the SRP19-RNA complex.
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pubmed:grant | |
pubmed:language |
eng
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pubmed:journal | |
pubmed:citationSubset |
IM
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pubmed:chemical | |
pubmed:status |
MEDLINE
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pubmed:month |
May
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pubmed:issn |
0014-2956
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pubmed:author | |
pubmed:issnType |
Print
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pubmed:day |
1
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pubmed:volume |
245
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pubmed:owner |
NLM
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pubmed:authorsComplete |
Y
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pubmed:pagination |
564-72
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pubmed:dateRevised |
2007-11-14
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pubmed:meshHeading |
pubmed-meshheading:9182991-Amino Acid Sequence,
pubmed-meshheading:9182991-Binding Sites,
pubmed-meshheading:9182991-Humans,
pubmed-meshheading:9182991-Molecular Sequence Data,
pubmed-meshheading:9182991-Mutagenesis, Site-Directed,
pubmed-meshheading:9182991-Plants,
pubmed-meshheading:9182991-Protein Binding,
pubmed-meshheading:9182991-Protein Structure, Secondary,
pubmed-meshheading:9182991-RNA,
pubmed-meshheading:9182991-Saccharomyces cerevisiae,
pubmed-meshheading:9182991-Sequence Analysis,
pubmed-meshheading:9182991-Signal Recognition Particle
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pubmed:year |
1997
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pubmed:articleTitle |
Identification of an RNA-binding-loop in the N-terminal region of signal-recognition-particle protein SRP19.
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pubmed:affiliation |
Department of Molecular Biology, The University of Texas Health Science Center at Tyler, 75710, USA.
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pubmed:publicationType |
Journal Article,
Research Support, U.S. Gov't, P.H.S.
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