PDBsum entry 1r7c

Membrane protein

PDB id: 1r7c

Contents

Protein chain

31 a.a.

PDB id:

1r7c

Name:

Membrane protein

Title:

Nmr structure of the membrane anchor domain (1-31) of the nonstructural protein 5a (ns5a) of hepatitis c virus (minimized average structure, sample in 50% tfe)

Structure:

Genome polyprotein. Chain: a. Fragment: nonstructural protein ns5a (p56)(residues 1973-2003 of swiss-prot sequence p27958). Engineered: yes

Source:

Synthetic: yes. Other_details: the peptide was chemically synthesized. The sequence is naturally found in hepatitis c virus.

NMR struc:

1 models

Authors:

F.Penin,V.Brass,N.Appel,S.Ramboarina,R.Montserret,D.Ficheux,H.E.Blum, R.Bartenschlager,D.Moradpour

Key ref:

F.Penin et al. (2004). Structure and function of the membrane anchor domain of hepatitis C virus nonstructural protein 5A. J Biol Chem, 279, 40835-40843. PubMed id: 15247283 DOI: 10.1074/jbc.M404761200

Date:

21-Oct-03 Release date: 10-Aug-04

Protein chain

P27958  (POLG_HCVH) -  Genome polyprotein from Hepatitis C virus genotype 1a (isolate H77)

Seq: 3011 a.a.

Struc: 31 a.a.

Enzyme reactions

• Enzyme class 1: E.C.2.7.7.48 - RNA-directed Rna polymerase.
• Reaction: RNA(n) + a ribonucleoside 5'-triphosphate = RNA(n+1) + diphosphate
• Enzyme class 2: E.C.3.4.21.98 - hepacivirin.
• Reaction: Hydrolysis of four peptide bonds in the viral precursor polyprotein, commonly with Asp or Glu in the P6 position, Cys or Thr in P1 and Ser or Ala in P1'.
• Enzyme class 3: E.C.3.4.22.- - ?????
• Enzyme class 4: E.C.3.6.1.15 - nucleoside-triphosphate phosphatase.
• Reaction: a ribonucleoside 5'-triphosphate + H2O = a ribonucleoside 5'-diphosphate + phosphate + H⁺
• Enzyme class 5: E.C.3.6.4.13 - Rna helicase.
• Reaction: ATP + H2O = ADP + phosphate + H⁺

Note, where more than one E.C. class is given (as above), each may correspond to a different protein domain or, in the case of polyprotein precursors, to a different mature protein.

Molecule diagrams generated from .mol files obtained from the KEGG ftp site

reference

DOI no: 10.1074/jbc.M404761200

J Biol Chem 279:40835-40843 (2004)

PubMed id: 15247283

Structure and function of the membrane anchor domain of hepatitis C virus nonstructural protein 5A.

F.Penin, V.Brass, N.Appel, S.Ramboarina, R.Montserret, D.Ficheux, H.E.Blum, R.Bartenschlager, D.Moradpour.

ABSTRACT

Hepatitis C virus (HCV) nonstructural protein 5A (NS5A) is a membrane-associated, essential component of the viral replication complex. Here, we report the three-dimensional structure of the membrane anchor domain of NS5A as determined by NMR spectroscopy. An alpha-helix extending from amino acid residue 5 to 25 was observed in the presence of different membrane mimetic media. This helix exhibited a hydrophobic, Trprich side embedded in detergent micelles, while the polar, charged side was exposed to the solvent. Thus, the NS5A membrane anchor domain forms an in-plane amphipathic alpha-helix embedded in the cytosolic leaflet of the membrane bilayer. Interestingly, mutations affecting the positioning of fully conserved residues located at the cytosolic surface of the helix impaired HCV RNA replication without interfering with the membrane association of NS5A. In conclusion, the NS5A membrane anchor domain constitutes a unique platform that is likely involved in specific interactions essential for the assembly of the HCV replication complex and that may represent a novel target for antiviral intervention.

Selected figure(s)

Figure 5.
FIG. 5. NS5A membrane anchor mutants. A, amino acid sequences of NS5A membrane anchor mutants. The amino acid conservation among different HCV isolates (20) is indicated by an asterisk (*), a colon (:), and a dot (.) for fully conserved, conserved, and similar residues, respectively. B and C, space-filling representation of theoretical helices for mutants 8+A and 11+A. An Ala insertion (shown in magenta) twists the helix by 110°. The C-terminal side of the helix is shown in the same orientation as in Fig. 3B to highlight the distortion of charged residues on the N-terminal side. Residues are colored as in Fig. 3B. These models were constructed by using the NMR average structure of NS5A[1-31] observed in 100 mM SDS as template and SwissPdb Viewer program (www.expasy.ch/swissmod/).

Figure 8.
FIG. 8. Membrane association of NS5A mutants. Hypotonic lysates of U-2 OS cells transiently transfected with pCMVNS5Acon, -8+A, -11+A, and - 5-11 were analyzed by centrifugation through Nycodenz gradients as described under "Experimental Procedures." Fractions were collected from the top and analyzed by immunoblot using mAbs 11H against NS5A and G1/296 against p63.

The above figures are reprinted by permission from the ASBMB: J Biol Chem (2004, 279, 40835-40843) copyright 2004.

Figures were selected by an automated process.