Quaternary structure and cleavage specificity of a poxvirus holliday junction resolvase

Quaternary structure and cleavage specificity of a poxvirus holliday junction resolvase
Engineering Village 2
2006 Elsevier Inc.
Accession number: 06249939894

Title: Quaternary structure and cleavage specificity of a poxvirus holliday junction resolvase

Authors: Garcia, Alonzo D.; Otero, Joel; Lebowitz, Jacob; Schuck, Peter; Moss, Bernard

Author affiliation: Laboratory of Viral Diseases, NIAID, National Institutes of Health, Bethesda, MD 20892, United States

Serial title: Journal of Biological Chemistry

Abbreviated serial title: J. Biol. Chem.

Volume: v 281

Issue: n 17

Issue date: Apr 28 2006

Publication year: 2006

Pages: p 11618-11626

Language: English

ISSN: 0021-9258


Document type: Journal article (JA)

Publisher: American Society for Biochemistry and Molecular Biology Inc., Bethesda, MD 20814, United States

Abstract: Recently, poxviruses were found to encode a protein with signature motifs present in the RuvC family of Holliday junction (HJ) resolvases, which have a key role in homologous recombination in bacteria. The vaccinia virus homolog A22 specifically cleaved synthetic HJDNA in vitro and was required for the in vivo resolution of viral DNA concatemers into unit-length genomes with hairpin telomeres. It was of interest to further characterize a poxvirus resolvase in view of the low sequence similarity with RuvC, the absence of virus-encoded RuvA and RuvB to interact with, and the different functions of the viral and bacterial resolvases. Because purified A22 aggregated severely, studies were carried out with maltose-binding protein fused to A22 as well as to RuvC. Using gel filtration, chemical cross-linking, analytical ultracentrifugation, and light scattering, we demonstrated that A22 and RuvC are homodimers in solution. Furthermore, the dimeric form of the resolvase associated with HJ DNA, presumably facilitating the symmetrical cleavage of such structures. Like RuvC, A22 symmetrically cleaved fixed HJ junctions as well as junctions allowing strand mobility. Unlike RuvC and other members of the family, however, the poxvirus enzyme exhibited little cleavage sequence specificity. Structural and enzymatic similarities of poxvirus, bacterial, and fungal mitochondrial HJ resolvases are consistent with their predicted evolutionary relationship based on sequence analysis. The absence of a homologous resolvase in mammalian cells makes these microbial enzymes excellent potential therapeutic targets.

Number of references: 21

Ei main heading: Enzymes

Ei controlled terms: Viruses - Bacteria - Vaccines - Genes - Maltose - Light scattering - Fungi - Cells

Uncontrolled terms: Holliday junction (HJ) - Chemical cross-linking - Analytical ultracentrifugation - Microbial enzymes - Fungal mitochondrial HJ resolvases

Ei classification codes: 461.9 Biology - 461.6 Medicine - 461.2 Biological Materials - 741.1 Light/Optics

Treatment: Theoretical (THR); Experimental (EXP)

DOI: 10.1074/jbc.M600182200

Database: Compendex

Compilation and indexing terms, ? 2006 Elsevier Inc. All rights reserved
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