1hh1
From Proteopedia
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THE STRUCTURE OF HJC, A HOLLIDAY JUNCTION RESOLVING ENZYME FROM SULFOLOBUS SOLFATARICUS
Overview
The 2.15-A structure of Hjc, a Holliday junction-resolving enzyme from the, archaeon Sulfolobus solfataricus, reveals extensive structural homology, with a superfamily of nucleases that includes type II restriction enzymes., Hjc is a dimer with a large DNA-binding surface consisting of numerous, basic residues surrounding the metal-binding residues of the active sites., Residues critical for catalysis, identified on the basis of sequence, comparisons and site-directed mutagenesis studies, are clustered to, produce two active sites in the dimer, about 29 A apart, consistent with, the requirement for the introduction of paired nicks in opposing strands, of the four-way DNA junction substrate. Hjc displays similarity to the, restriction endonucleases in the way its specific DNA-cutting pattern is, determined but uses a different arrangement of nuclease subunits. Further, structural similarity to a broad group of metal/phosphate-binding, proteins, including conservation of active-site location, is observed. A, high degree of conservation of surface electrostatic character is observed, between Hjc and T4-phage endonuclease VII despite a complete lack of, structural homology. A model of the Hjc-Holliday junction complex is, proposed, based on the available functional and structural data.
About this Structure
1HH1 is a Single protein structure of sequence from Sulfolobus solfataricus. Full crystallographic information is available from OCA.
Reference
Structure of Hjc, a Holliday junction resolvase, from Sulfolobus solfataricus., Bond CS, Kvaratskhelia M, Richard D, White MF, Hunter WN, Proc Natl Acad Sci U S A. 2001 May 8;98(10):5509-14. Epub 2001 May 1. PMID:11331763
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