Fig. 3. X-ray structures of the HCV NS3-4A serine protease.
Fig. 3. X-ray structures of the HCV NS3-4A serine protease.

Fig. 3

X-ray structures of the HCV NS3-4A serine protease.

(A) Ribbon diagram of the NS3 protease domain in a complex with an NS4A cofactor peptide. The N-terminal sub-domain of the NS3 protease (in green), including the NS4A β-strand (in magenta), is on the left side and the C-terminal sub-domain (in green) on the right side. Shown in ball-and-stick are the catalytic triad, His57, Asp81, and Ser139, at the top, and the zinc atom (in cyan), which is tetrahedrally coordinated by three Cys residues (Cys97, Cys99, and Cys145) (in yellow spheres) and, via a water molecule (in red), His149 (not shown), at the bottom.

(B) A close-up view of the zinc-binding site. Shown in ball-and-stick presentation is the zinc atom (in cyan), which is coordinated by three Cys residues (Cys97, Cys99, and Cys145) (in yellow spheres) and, via a water molecule (W, in red sphere), His149.

(C) Stick diagram of interaction between the two N-terminal β-strands of the NS3 serine protease domain (thin bonds) and the NS4A activating cofactor (thick bonds). Several residues in the central region of NS4A cofactor, including Val23, Ile25, Ile29, and Leu31, make extensive hydrophobic interaction with many hydrophobic side chains of these two β-strands of the NS3 protease that form a “sandwich” with the NS4A β-strand. NS4A also forms numerous main-chain hydrogen bonds with these NS3 residues. (Reprinted from Cell (1996) 87: 343–355, J.L. Kim et al., Crystal structure of the hepatitis C virus NS3 protease domain complexed with a synthetic NS4A cofactor peptide. With permission from Elsevier.)

From: Chapter 6, HCV NS3-4A Serine Protease

Cover of Hepatitis C Viruses
Hepatitis C Viruses: Genomes and Molecular Biology.
Tan SL, editor.
Norfolk (UK): Horizon Bioscience; 2006.
Copyright © 2006, Horizon Bioscience.

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