Linked Life Data

11846566

Source:http://linkedlifedata.com/resource/pubmed/id/11846566

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
2002-2-15
pubmed:databankReference
pubmed:abstractText
The NS3 protein of the hepatitis C virus (HCV) is a 631 amino acid residue bifunctional enzyme with a serine protease localized to the N-terminal 181 residues and an RNA helicase located in the C-terminal 450 residues. The HCV NS3 RNA helicase consists of three well-defined subdomains which all contribute to its helicase activity. The second subdomain of the HCV helicase is flexibly linked to the remainder of the NS3 protein and could undergo rigid-body movements during the unwinding of double-stranded RNA. It also contains several motifs that are implicated in RNA binding and in coupling NTP hydrolysis to nucleic acid unwinding and translocation. As part of our efforts to use NMR techniques to assist in deciphering the enzyme's structure-function relationships and developing specific small molecule inhibitors, we have determined the solution structure of an engineered subdomain 2 of the NS3 RNA helicase of HCV, d(2Delta)-HCVh, and studied the backbone dynamics of this protein by (15)N-relaxation experiments using a model-free approach. The NMR studies on this 142-residue construct reveal that overall subdomain 2 of the HCV helicase is globular and well structured in solution even in the absence of the remaining parts of the NS3 protein. Its solution structure is very similar to the corresponding parts in the X-ray structures of the HCV NS3 helicase domain and intact bifunctional HCV NS3 protein. Slow hydrogen-deuterium exchange rates map to a well-structured, stable hydrophobic core region away from the subdomain interfaces. In contrast, the regions facing the subdomain interfaces in the HCV NS3 helicase domain are less well structured in d(2Delta)-HCVh, show fast hydrogen-deuterium exchange rates, and the analysis of the dynamic properties of d(2Delta)-HCVh reveals that these regions of the protein show distinct dynamical features. In particular, residues in motif V, which may be involved in transducing allosteric effects of nucleotide binding and hydrolysis on RNA binding, exhibit slow conformational exchange on the milli- to microsecond time-scale. The intrinsic conformational flexibility of this loop region may facilitate conformational changes required for helicase function.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Nov
pubmed:issn
0022-2836
pubmed:author
pubmed:copyrightInfo
Copyright 2001 Academic Press.
pubmed:issnType
Print
pubmed:day
30
pubmed:volume
314
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
543-61
pubmed:meshHeading
pubmed-meshheading:11846566-Amino Acid Motifs, pubmed-meshheading:11846566-Arginine, pubmed-meshheading:11846566-Deuterium, pubmed-meshheading:11846566-Hepacivirus, pubmed-meshheading:11846566-Hydrogen, pubmed-meshheading:11846566-Kinetics, pubmed-meshheading:11846566-Models, Molecular, pubmed-meshheading:11846566-Nuclear Magnetic Resonance, Biomolecular, pubmed-meshheading:11846566-Peptide Fragments, pubmed-meshheading:11846566-Pliability, pubmed-meshheading:11846566-Protein Engineering, pubmed-meshheading:11846566-Protein Structure, Secondary, pubmed-meshheading:11846566-Protein Structure, Tertiary, pubmed-meshheading:11846566-RNA Helicases, pubmed-meshheading:11846566-Solutions, pubmed-meshheading:11846566-Structure-Activity Relationship, pubmed-meshheading:11846566-Viral Nonstructural Proteins
pubmed:year
2001
pubmed:articleTitle
Solution structure and backbone dynamics of an engineered arginine-rich subdomain 2 of the hepatitis C virus NS3 RNA helicase.
pubmed:affiliation
Department of Structural Chemistry, Schering-Plough Research Institute, 2015 Galloping Hill Road, Kenilworth, NJ 07033, USA.
pubmed:publicationType
Journal Article