1VK1: Conserved Hypothetical Protein From Pyrococcus Furiosus Pfu-392566-001

BACKGROUND: The major bottleneck for determination of 3 D structures of proteins using X-rays is the production of diffraction quality crystals. Often proteins are subjected to chemical modification to improve the chances of crystallization RESULTS: Here, we report the successful crystallization of a nuclease employing a reductive methylation protocol. The key to crystallization was the successful introduction of 44 new cohesive (NZ) CH...O contacts (3.2-3.7 A) by the addition of 2 methyl groups to the side chain amine nitrogen (NZ) of 9 lysine residues of the nuclease. The new contacts dramatically altered the crystallization properties of the protein, resulting in crystals that diffracted to 1.2 A resolution. Analytical ultracentrifugation analysis and thermodynamics results revealed a more compact protein structure with better solvent exclusion of buried Trp residues in the folded state of the methylated protein, assisting crystallization. CONCLUSION: In this study, introduction of novel cohesive (NZ)CH...O contacts by reductive methylation resulted in the crystallization of a protein that had previously resisted crystallization in spite of extensive purification and crystallization space screening. Introduction of (NZ)CH...O contacts could provide a solution to crystallization problems for a broad range of protein targets.
PDB ID: 1VK1Download
MMDB ID: 29190
PDB Deposition Date: 2004/4/13
Updated in MMDB: 2008/12
Experimental Method:
x-ray diffraction
Resolution: 1.2  Å
Source Organism:
Similar Structures:
Biological Unit for 1VK1: monomeric; determined by author
Molecular Components in 1VK1
Label Count Molecule
Protein (1 molecule)
Conserved Hypothetical Protein
Molecule annotation
Chemicals (3 molecules)
* Click molecule labels to explore molecular sequence information.

Citing MMDB